db: add function apk_repository_update_all

We might want to add an --update-index option to misc applets. For
example:

  apk add --update-index -u package
  apk version --update-index

src/apk_database.h

@@ -130,6 +130,7 @@ int apk_db_index_write(struct apk_database *db, struct apk_ostream *os);
 
 int apk_db_add_repository(apk_database_t db, apk_blob_t repository);
 int apk_repository_update(struct apk_database *db, struct apk_repository *repo);
+int apk_repository_update_all(struct apk_database *db);
 
 int apk_db_install_pkg(struct apk_database *db,
 		       struct apk_package *oldpkg,

src/database.c

@@ -959,6 +959,17 @@ int apk_repository_update(struct apk_database *db, struct apk_repository *repo)
 	return 0;
 }
 
+int apk_repository_update_all(struct apk_database *db)
+{
+	int i, ret;
+	for (i = 0; i < db->num_repos; i++) {
+		ret = apk_repository_update(db, &db->repos[i]);
+		if (ret < 0)
+			return ret;
+	}
+	return 0;
+}
+
 int apk_db_add_repository(apk_database_t _db, apk_blob_t repository)
 {
 	struct apk_database *db = _db.db;

src/update.c

@@ -18,14 +18,11 @@
 static int update_main(void *ctx, int argc, char **argv)
 {
 	struct apk_database db;
-	int i;
 
 	if (apk_db_open(&db, apk_root, APK_OPENF_READ) < 0)
 		return -1;
 
-	for (i = 0; i < db.num_repos; i++)
-		apk_repository_update(&db, &db.repos[i]);
-
+	apk_repository_update_all(&db);
 	apk_db_close(&db);
 
 	return 0;