ghmerge: Add missing ;;

Reviewed-by: Richard Levitte <[email protected]>
(Merged from #213)

Author: t8m

review-tools/ghmerge

@@ -64,6 +64,7 @@ while [ $# -ne 0 ]; do
         ;;
     --perftools)
         WHAT=perftools; BUILD=no; shift
+        ;;
     --installer)
         WHAT=installer ; BUILD=no ; shift
         ;;