gnu: openssh: Use G-expressions.

* gnu/packages/ssh.scm (openssh)[arguments]:
Rewrite as G-expressions.

gnu/packages/ssh.scm

@@ -209,64 +209,44 @@ a server that supports the SSH-2 protocol.")
               (base32
                "1s3nqv57r3l7avsdkzwd575dvxra8h19xpqczl0z3cvcgwabw3i0"))))
    (build-system gnu-build-system)
-   (native-inputs (list groff pkg-config))
-   (inputs
-    (cons* libedit
-           openssl
-           mit-krb5
-           zlib
-           xauth                        ; for 'ssh -X' and 'ssh -Y'
-           (if (target-hurd?)
-               '()
-               (list linux-pam
-                     libfido2))))       ; fails to build on GNU/Hurd
    (arguments
-    `(#:test-target "tests"
-      ;; Otherwise, the test scripts try to use a nonexistent directory and
-      ;; fail.
-      #:make-flags '("REGRESSTMP=\"$${BUILDDIR}/regress\"")
-      #:configure-flags  `("--sysconfdir=/etc/ssh"
-
+    (list
+     #:test-target "tests"
+     ;; Otherwise, the test scripts try to use a nonexistent directory and fail.
+     #:make-flags
+     #~(list "REGRESSTMP=\"$${BUILDDIR}/regress\"")
+     #:configure-flags
+     #~(append
+        (list "--sysconfdir=/etc/ssh"
               ;; Default value of 'PATH' used by sshd.
               "--with-default-path=/run/current-system/profile/bin"
-
               ;; configure needs to find krb5-config.
-                          ,(string-append "--with-kerberos5="
-                                          (assoc-ref %build-inputs "mit-krb5")
+              (string-append "--with-kerberos5="
+                             #$(this-package-input "mit-krb5")
                              "/bin")
-
               ;; libedit is needed for sftp completion.
-                          "--with-libedit"
-
+              "--with-libedit")
         ;; Enable PAM support in sshd.
-                          ,,@(if (target-hurd?)
+        (if #$(target-hurd?)
             '()
-                               '("--with-pam"
-
-                                 ;; Support creation and use of ecdsa-sk,
-                                 ;; ed25519-sk keys.
+            (list "--with-pam"
+                  ;; Support creation and use of ecdsa-sk, ed25519-sk keys.
                   "--with-security-key-builtin"))
-
-
-
-                          ;; "make install" runs "install -s" by default,
-                          ;; which doesn't work for cross-compiled binaries
-                          ;; because it invokes 'strip' instead of
+        ;; "make install" runs "install -s" by default, which doesn't work for
+        ;; cross-compiled binaries because it invokes 'strip' instead of
         ;; 'TRIPLET-strip'.  Work around this.
-                          ,,@(if (%current-target-system)
-                                 '("--disable-strip")
+        (if #$(%current-target-system)
+            (list "--disable-strip")
             '()))
-
      #:phases
-      (modify-phases %standard-phases
+     #~(modify-phases %standard-phases
          (add-after 'configure 'reset-/var/empty
-         (lambda* (#:key outputs #:allow-other-keys)
-           (let ((out (assoc-ref outputs "out")))
+           (lambda _
              (substitute* "Makefile"
                (("PRIVSEP_PATH=/var/empty")
-                (string-append "PRIVSEP_PATH=" out "/var/empty"))))))
+                (string-append "PRIVSEP_PATH=" #$output "/var/empty")))))
          (add-after 'configure 'set-store-location
-          (lambda* _
+           (lambda _
              (substitute* "misc.c"
                (("@STORE_DIRECTORY@")
                 (string-append "\"" (%store-directory) "\"")))))
@@ -281,18 +261,28 @@ a server that supports the SSH-2 protocol.")
                (("^(tests:.*) t-exec(.*)" all pre post)
                 (string-append pre post)))))
          (replace 'install
-          (lambda* (#:key outputs (make-flags '()) #:allow-other-keys)
-            (let ((out (assoc-ref outputs "out")))
-              ;; Install without host keys and system configuration files.
-              ;; This will install /var/empty to the store, which is needed
-              ;; by the system openssh-service-type.
+           (lambda* (#:key (make-flags '()) #:allow-other-keys)
+             ;; Install without host keys and system configuration files.  This
+             ;; will install /var/empty to the store, which is needed by the
+             ;; system openssh-service-type.
              (apply invoke "make" "install-nosysconf" make-flags)
              (with-directory-excursion "contrib"
                (chmod "ssh-copy-id" #o555)
                (install-file "ssh-copy-id"
-                              (string-append out "/bin/"))
+                             (string-append #$output "/bin/"))
                (install-file "ssh-copy-id.1"
-                              (string-append out "/share/man/man1/")))))))))
+                             (string-append #$output "/share/man/man1/"))))))))
+   (native-inputs (list groff pkg-config))
+   (inputs
+    (cons* libedit
+           openssl
+           mit-krb5
+           zlib
+           xauth                        ; for 'ssh -X' and 'ssh -Y'
+           (if (target-hurd?)
+               '()
+               (list linux-pam
+                     libfido2))))       ; fails to build on GNU/Hurd
    (synopsis "Client and server for the secure shell (ssh) protocol")
    (description
     "The SSH2 protocol implemented in OpenSSH is standardised by the