import: Fix docstring typoes.

* guix/import/cabal.scm (cabal-flags->alist): Fix typo in docstring.
* guix/import/stackage.scm (lts-info-ghc-version): Likewise.
* guix/scripts/import/hackage.scm (show-help): Likewise.

guix/import/cabal.scm

@@ -718,7 +718,7 @@ If #f use the function 'port-filename' to obtain it."
   (dependencies cabal-custom-setup-dependencies)) ; list of <cabal-dependency>
 
 (define (cabal-flags->alist flag-list)
-    "Retrun an alist associating the flag name to its default value from a
+    "Return an alist associating the flag name to its default value from a
 list of <cabal-flag> objects."
   (map (lambda (flag) (cons (cabal-flag-name flag) (cabal-flag-default flag)))
        flag-list))

guix/import/stackage.scm

@@ -42,12 +42,12 @@
 (define %stackage-url "http://www.stackage.org")
 
 (define (lts-info-ghc-version lts-info)
-  "Retruns the version of the GHC compiler contained in LTS-INFO."
+  "Returns the version of the GHC compiler contained in LTS-INFO."
   (and=> (assoc-ref lts-info "snapshot")
          (cut assoc-ref <> "ghc")))
 
 (define (lts-info-packages lts-info)
-  "Retruns the alist of packages contained in LTS-INFO."
+  "Returns the alist of packages contained in LTS-INFO."
   (or (assoc-ref lts-info "packages") '()))
 
 (define (leave-with-message fmt . args)

guix/scripts/import/hackage.scm

@@ -49,7 +49,7 @@
 Import and convert the Hackage package for PACKAGE-NAME.  If PACKAGE-NAME
 includes a suffix constituted by a at-sign followed by a numerical version (as
 used with Guix packages), then a definition for the specified version of the
-package will be generated.  If no version suffix is pecified, then the
+package will be generated.  If no version suffix is specified, then the
 generated package definition will correspond to the latest available
 version.\n"))
   (display (G_ "