cocci: apply the "cache.h" part of "the_repository.pending"

Apply the part of "the_repository.pending.cocci" pertaining to
"cache.h".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

add-patch.c

@@ -414,7 +414,7 @@ static int parse_diff(struct add_p_state *s, const struct pathspec *ps)
 		strvec_push(&args,
 			    /* could be on an unborn branch */
 			    !strcmp("HEAD", s->revision) &&
-			    get_oid("HEAD", &oid) ?
+			    repo_get_oid(the_repository, "HEAD", &oid) ?
 			    empty_tree_oid_hex() : s->revision);
 	}
 	color_arg_index = args.nr;