[PATCH] diff-cache path restriction fix.

[Junio C Hamano <junkio@cox.net>]

It advertises the path restriction in documentation and usage
string, but the argument parsing code was not updated and was
causing it to refuse to run.  One liner fix is here.

Signed-off-by: Junio C Hamano <junkio@cox.net>
---
# - linus: git-update-cache: allow dot-files
# + (working tree)
diff --git a/diff-cache.c b/diff-cache.c
--- a/diff-cache.c
+++ b/diff-cache.c
@@ -164,7 +164,7 @@ int main(int argc, const char **argv)
 	int ret;
 
 	read_cache();
-	while (argc > 2) {
+	while (1 < argc && argv[1][0] == '-') {
 		const char *arg = argv[1];
 		argv++;
 		argc--;