gnu: emacs-volatile-highlights: Fix build.

* gnu/packages/emacs-xyz.scm (emacs-volatile-highlights): Use git tag instead
of commit hash.

Change-Id: I2977b6c7db9826e79278548a7b7f97c8099df0c3

gnu/packages/emacs-xyz.scm

@@ -39947,20 +39947,18 @@ Validator service and displays the results in a buffer in Compilation mode.")
       (license license:gpl3+))))
 
 (define-public emacs-volatile-highlights
-  ;; XXX: Upstream does not tag releases.  Commit below matches version bump.
-  (let ((commit "9a20091f0ce7fc0a6b3e641a6a46d5f3ac4d8392"))
-    (package
+  (package
     (name "emacs-volatile-highlights")
     (version "1.16")
     (source (origin
-             (method git-fetch)
-             (uri (git-reference
-                   (url "http://github.com/k-talo/volatile-highlights.el")
-                   (commit commit)))
-             (file-name (git-file-name name version))
-             (sha256
-              (base32
-               "0rlqwj6whxbvzgkf78d8arjva49aphj4bd2wkpv8djykcmi8nf6m"))))
+              (method git-fetch)
+              (uri (git-reference
+                    (url "http://github.com/k-talo/volatile-highlights.el")
+                    (commit (string-append "v" version))))
+              (file-name (git-file-name name version))
+              (sha256
+               (base32
+                "1dsa6769lphyyv7yg92vkkpk395w52q4m7hdn8xy7s6lh5c6a955"))))
     (build-system emacs-build-system)
     (home-page "http://github.com/k-talo/volatile-highlights.el")
     (synopsis "Emacs minor mode for visual feedback on some operations")
@@ -39968,7 +39966,7 @@ Validator service and displays the results in a buffer in Compilation mode.")
 some operations by highlighting portions relating to the operations.  All of
 highlights made by this library will be removed when any new operation is
 executed.")
-    (license license:gpl3+))))
+    (license license:gpl3+)))
 
 (define-public emacs-global-tags
   (let ((commit "06db25d91cc8bfb5e24e02adc04de1226c7e742d")