apply changes from reviews

Author: LamentXU123

ext/json/json_encoder.c

@@ -54,17 +54,10 @@ static inline void php_json_pretty_print_char(smart_str *buf, int options, char
 static inline void php_json_pretty_print_indent(smart_str *buf, int options, const php_json_encoder *encoder) /* {{{ */
 {
 	if (options & PHP_JSON_PRETTY_PRINT) {
-		static const char spaces[] =
-			"                                                                ";
 		size_t remaining = (size_t) encoder->depth * 4;
-
-		while (remaining >= sizeof(spaces) - 1) {
-			smart_str_appendl(buf, spaces, sizeof(spaces) - 1);
-			remaining -= sizeof(spaces) - 1;
-		}
-
 		if (remaining) {
-			smart_str_appendl(buf, spaces, remaining);
+			char *dst = smart_str_extend(buf, remaining);
+			memset(dst, ' ', remaining);
 		}
 	}
 }