Silence calls to git in version.sh.

Originally committed as revision 21068 to svn://svn.ffmpeg.org/ffmpeg/trunk

version.sh

@@ -12,13 +12,13 @@ test $revision && revision=SVN-r$revision
 
 # check for git svn revision number
 if ! test $revision; then
-    revision=$(cd "$1" && git svn find-rev HEAD)
+    revision=$(cd "$1" && git svn find-rev HEAD 2> /dev/null)
     test $revision && revision=git-svn-r$revision
 fi
 
 # check for git short hash
 if ! test $revision; then
-    revision=$(cd "$1" && git log -1 --pretty=format:%h)
+    revision=$(cd "$1" && git log -1 --pretty=format:%h 2> /dev/null)
     test $revision && revision=git-$revision
 fi