gnu: hypre: Don't use unstable tarball.

* gnu/packages/maths.scm (hypre)[source]: Use GIT-FETCH and
GIT-FILE-NAME.

gnu/packages/maths.scm

@@ -3680,14 +3680,15 @@ set.")
   (package
     (name "hypre")
     (version "2.14.0")
-    (source (origin
-              (method url-fetch)
-              (uri (string-append "https://github.com/LLNL/hypre/archive/"
-                                  "v" version ".tar.gz"))
-              (file-name (string-append name "-" version ".tar.gz"))
+    (source
+     (origin
+       (method git-fetch)
+       (uri (git-reference
+             (url "https://github.com/LLNL/hypre.git")
+             (commit (string-append "v" version))))
+       (file-name (git-file-name name version))
        (sha256
-               (base32
-                "0v515i73bvaz378h5465b1dy9v2gf924zy2q94cpq4qqarawvkqh"))
+        (base32 "12iciad718rf7vcl33klza7dcnxxa5581yav7c72l81m7mswihq9"))
        (modules '((guix build utils)))
        (snippet
         '(begin