ext/curl: Use Z_ARRVAL_P instead of HASH_OF

We already check in advance that it is an array

ext/curl/interface.c

@@ -1540,7 +1540,7 @@ static inline zend_result build_mime_structure_from_hash(php_curl *ch, zval *zpo
 		if (Z_TYPE_P(current) == IS_ARRAY) {
 			zval *current_element;
 
-			ZEND_HASH_FOREACH_VAL(HASH_OF(current), current_element) {
+			ZEND_HASH_FOREACH_VAL(Z_ARRVAL_P(current), current_element) {
 				add_simple_field(mime, string_key, current_element);
 			} ZEND_HASH_FOREACH_END();
 
@@ -2186,7 +2186,7 @@ static zend_result _php_curl_setopt(php_curl *ch, zend_long option, zval *zvalue
 
 		case CURLOPT_POSTFIELDS:
 			if (Z_TYPE_P(zvalue) == IS_ARRAY) {
-				if (zend_hash_num_elements(HASH_OF(zvalue)) == 0) {
+				if (zend_hash_num_elements(Z_ARRVAL_P(zvalue)) == 0) {
 					/* no need to build the mime structure for empty hashtables;
 					   also works around https://github.com/curl/curl/issues/6455 */
 					curl_easy_setopt(ch->cp, CURLOPT_POSTFIELDS, "");