gnu: nsd: Use G-expressions.

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

gnu/packages/dns.scm

@@ -523,16 +523,17 @@ the two.")
         (base32 "057jxhhyggqhy4swwqlwf1lflc96cfqpm200l1gr3lls557a9b4g"))))
     (build-system gnu-build-system)
     (arguments
-     `(#:configure-flags
-       (list "--enable-pie"             ; fully benefit from ASLR
+     (list
+      #:configure-flags
+      #~(list "--enable-pie"            ; fully benefit from tasty ASLR
               "--enable-ratelimit"
               "--enable-recvmmsg"
               "--enable-relro-now"      ; protect GOT and .dtor areas
               "--disable-radix-tree"
               (string-append "--with-libevent="
-                            (assoc-ref %build-inputs "libevent"))
+                             #$(this-package-input "libevent"))
               (string-append "--with-ssl="
-                            (assoc-ref %build-inputs "openssl"))
+                             #$(this-package-input "openssl"))
               "--with-configdir=/etc"
               "--with-nsd_conf_file=/etc/nsd/nsd.conf"
               "--with-logfile=/var/log/nsd.log"
@@ -542,11 +543,11 @@ the two.")
               "--with-xfrdfile=/var/db/nsd/xfrd.state"
               "--with-zonelistfile=/var/db/nsd/zone.list")
       #:phases
-       (modify-phases %standard-phases
+      #~(modify-phases %standard-phases
           (add-before 'configure 'patch-installation-paths
-           (lambda* (#:key outputs #:allow-other-keys)
-             (let* ((out (assoc-ref outputs "out"))
-                    (doc (string-append out "/share/doc/" ,name "-" ,version)))
+            (lambda _
+              (let ((doc (string-append #$output "/share/doc/"
+                                        #$name "-" #$version)))
                 ;; The ‘make install’ target tries to create the parent
                 ;; directories of run-time things like ‘pidfile’ above, and
                 ;; useless empty directories like 'configdir'.  Remove such