g: fix var in checkout

Change-Id: Ie414037671ca9248931a47000db2b4ed259e72da
Reviewed-on: https://gerrit.libreoffice.org/21217Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Michael Stahl <mstahl@redhat.com>

g

@@ -213,7 +213,7 @@ local module
 	elif [ "$cmd" = "-b" ] ; then
 	    create_branch=1
 	elif [ "$create_branch" = "1" ] ; then
-	    branch="$arg"
+	    branch="$cmd"
 	    create_branch=0
 	fi
     done