gnu: squashfs-tools: Build from upstream git.

* gnu/packages/compression.scm (squashfs-tools)[source]: Use GIT-FETCH
and GIT-FILE-NAME.

gnu/packages/compression.scm

@@ -856,14 +856,15 @@ time for compression ratio.")
   (package
     (name "squashfs-tools")
     (version "4.4")
-    (source (origin
-              (method url-fetch)
-              (uri (string-append "mirror://sourceforge/squashfs/squashfs/"
-                                  "squashfs" version "/"
-                                  "squashfs" version ".tar.gz"))
+    (source
+     (origin
+       (method git-fetch)
+       (uri (git-reference
+             (url "https://github.com/plougher/squashfs-tools")
+             (commit version)))
+       (file-name (git-file-name name version))
        (sha256
-               (base32
-                "0zmhvczscqz0mzh4b9m8m42asq14db0a6lc8clp5ljq5ybrv70d9"))
+        (base32 "0697fv8n6739mcyn57jclzwwbbqwpvjdfkv1qh9s56lvyqnplwaw"))
        (modules '((guix build utils)))
        (snippet
         '(begin