name-hash.c: replace cache_name_compare() with memcmp(3)

The same_name() private function wants a quick-and-exact check to
see if they two names are byte-for-byte identical first and then
fall back to the slow path.  Use memcmp(3) for the former to make it
clear that we do not want any "name" specific comparison.

Signed-off-by: Jeremiah Mahler <jmmahler@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

name-hash.c

@@ -179,7 +179,7 @@ static int same_name(const struct cache_entry *ce, const char *name, int namelen
 	 * Always do exact compare, even if we want a case-ignoring comparison;
 	 * we do the quick exact one first, because it will be the common case.
 	 */
-	if (len == namelen && !cache_name_compare(name, namelen, ce->name, len))
+	if (len == namelen && !memcmp(name, ce->name, len))
 		return 1;
 
 	if (!icase)