fix gdb version parsing in src-release.sh

Small change required after we switched the gdb version scheme to
using a -git suffix rather than a -cvs one.

ChangeLog:

        * src-release.sh: Compute the gdb tarball name by stripping
        '-git' rather than '-cvs'.

Tested by running "src-release.sh gdb" and verifying the tarball
name as well as its contents.

src-release.sh

@@ -60,7 +60,7 @@ getver()
 	bfd/configure --version | sed -n -e '1s,.* ,,p'
     elif test -f $tool/common/create-version.sh; then
 	$tool/common/create-version.sh $tool 'dummy-host' 'dummy-target' VER.tmp
-	cat VER.tmp | grep 'version\[\]' | sed 's/.*"\([^"]*\)".*/\1/' | sed 's/-cvs$//'
+	cat VER.tmp | grep 'version\[\]' | sed 's/.*"\([^"]*\)".*/\1/' | sed 's/-git$//'
         rm -f VER.tmp
     elif test -f $tool/version.in; then
 	head -1 $tool/version.in