aws_credentials_sts: internal: Use early return when allocation is failed

Signed-off-by: Hiroshi Hatake <hiroshi@chronosphere.io>

Author: cosmo0920

tests/internal/aws_credentials_sts.c

@@ -305,6 +305,9 @@ struct flb_http_client *request_sts_test1(struct flb_aws_client *aws_client,
     mk_list_init(&c->headers);
     payload = build_sts_response_with_ttl_calloc(3600, &payload_len);
     TEST_CHECK(payload != NULL);
+    if (!payload) {
+        return NULL;
+    }
 
     http_test_attach_owned_payload(c, payload, payload_len);
 
@@ -469,6 +472,9 @@ static void test_process_sts_response()
     }
     payload = build_eks_response_with_ttl_calloc(3600, &payload_len);
     TEST_CHECK(payload != NULL);
+    if (!payload) {
+        return NULL;
+    }
 
     creds = flb_parse_sts_resp(payload, &expiration);