ls-tree: disable negative pathspec because it's not supported

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/ls-tree.c

@@ -174,7 +174,8 @@ int cmd_ls_tree(int argc, const char **argv, const char *prefix)
 	 * cannot be lifted until it is converted to use
 	 * match_pathspec() or tree_entry_interesting()
 	 */
-	parse_pathspec(&pathspec, PATHSPEC_GLOB | PATHSPEC_ICASE,
+	parse_pathspec(&pathspec, PATHSPEC_GLOB | PATHSPEC_ICASE |
+				  PATHSPEC_EXCLUDE,
 		       PATHSPEC_PREFER_CWD,
 		       prefix, argv + 1);
 	for (i = 0; i < pathspec.nr; i++)