test: Avoid matching three X's

This helps my "WIP" detector script avoid false positives. It is a
simple script which helps me find release critical problems.

test/test-govet.sh

@@ -22,7 +22,8 @@ function simplify-gocase() {
 }
 
 function token-coloncheck() {
-	if grep -Ei "[\/]+[\/]+[ ]*+(FIXME[^:]|TODO[^:]|XXX[^:])" "$1"; then
+	# add quotes to avoid matching three X's
+	if grep -Ei "[\/]+[\/]+[ ]*+(FIXME[^:]|TODO[^:]|X"'X'"X[^:])" "$1"; then
 		return 1	# tokens must end with a colon
 	fi
 	return 0