more oideq/hasheq conversions

We added faster equality-comparison functions for hashes in
14438c44 (introduce hasheq() and oideq(), 2018-08-28). A
few topics were in-flight at the time, and can now be
converted. This covers all spots found by "make coccicheck"
in master (the coccicheck results were tweaked by hand for
style).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

builtin/checkout.c

@@ -497,7 +497,8 @@ static int skip_merge_working_tree(const struct checkout_opts *opts,
 	 * We must do the merge if we are actually moving to a new commit.
 	 */
 	if (!old_branch_info->commit || !new_branch_info->commit ||
-		oidcmp(&old_branch_info->commit->object.oid, &new_branch_info->commit->object.oid))
+		!oideq(&old_branch_info->commit->object.oid,
+		       &new_branch_info->commit->object.oid))
 		return 0;
 
 	/*

cache-tree.c

@@ -781,7 +781,7 @@ static void verify_one(struct index_state *istate,
 		strbuf_add(&tree_buf, oid->hash, the_hash_algo->rawsz);
 	}
 	hash_object_file(tree_buf.buf, tree_buf.len, tree_type, &new_oid);
-	if (oidcmp(&new_oid, &it->oid))
+	if (!oideq(&new_oid, &it->oid))
 		BUG("cache-tree for path %.*s does not match. "
 		    "Expected %s got %s", len, path->buf,
 		    oid_to_hex(&new_oid), oid_to_hex(&it->oid));

commit-reach.c

@@ -426,7 +426,7 @@ struct contains_stack {
 static int in_commit_list(const struct commit_list *want, struct commit *c)
 {
 	for (; want; want = want->next)
-		if (!oidcmp(&want->item->object.oid, &c->object.oid))
+		if (oideq(&want->item->object.oid, &c->object.oid))
 			return 1;
 	return 0;
 }

midx.c

@@ -285,8 +285,8 @@ static int nth_midxed_pack_entry(struct multi_pack_index *m, struct pack_entry *
 		struct object_id oid;
 		nth_midxed_object_oid(&oid, m, pos);
 		for (i = 0; i < p->num_bad_objects; i++)
-			if (!hashcmp(oid.hash,
-				     p->bad_object_sha1 + the_hash_algo->rawsz * i))
+			if (hasheq(oid.hash,
+				   p->bad_object_sha1 + the_hash_algo->rawsz * i))
 				return 0;
 	}
 
@@ -583,8 +583,8 @@ static struct pack_midx_entry *get_sorted_entries(struct multi_pack_index *m,
 		 * Take only the first duplicate.
 		 */
 		for (cur_object = 0; cur_object < nr_fanout; cur_object++) {
-			if (cur_object && !oidcmp(&entries_by_fanout[cur_object - 1].oid,
-						  &entries_by_fanout[cur_object].oid))
+			if (cur_object && oideq(&entries_by_fanout[cur_object - 1].oid,
+						&entries_by_fanout[cur_object].oid))
 				continue;
 
 			ALLOC_GROW(deduplicated_entries, *nr_objects + 1, alloc_objects);