fixup! clean: do not traverse mount points

This compile error fix was inadvertently squashed into 379fe49
(clean: remove mount points when possible, 2018-12-11), but actually
belongs into an earlier patch.

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

builtin/clean.c

@@ -175,7 +175,7 @@ static int remove_dirs(struct strbuf *path, const char *prefix, int force_flag,
 
 	if (is_mount_point(path)) {
 		if (!quiet) {
-			quote_path_relative(path->buf, prefix, &quoted);
+			quote_path(path->buf, prefix, &quoted, 0);
 			printf(dry_run ?
 			       _(msg_would_skip_mount_point) :
 			       _(msg_skip_mount_point), quoted.buf);