cache_tree_find(): use path variable when passing over slashes

The search for the end of the slashes is part of the update of the
path variable for the next iteration as opposed to an update of the
slash variable.  So iterate using path rather than slash.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

cache-tree.c

@@ -563,9 +563,10 @@ static struct cache_tree *cache_tree_find(struct cache_tree *it, const char *pat
 		if (!sub)
 			return NULL;
 		it = sub->cache_tree;
-		while (*slash == '/')
-			slash++;
+
 		path = slash;
+		while (*path == '/')
+			path++;
 	}
 	return it;
 }