Prevent use after stack scope in stream strerr code (php#20040)

Author: bukka

main/streams/streams.c

@@ -155,6 +155,7 @@ static void php_stream_display_wrapper_errors(php_stream_wrapper *wrapper, const
 {
 	char *tmp;
 	char *msg;
+	char errstr[256];
 	int free_msg = 0;
 
 	if (EG(exception)) {
@@ -204,7 +205,6 @@ static void php_stream_display_wrapper_errors(php_stream_wrapper *wrapper, const
 			free_msg = 1;
 		} else {
 			if (wrapper == &php_plain_files_wrapper) {
-				char errstr[256];
 				msg = php_socket_strerror_s(errno, errstr, sizeof(errstr));
 			} else {
 				msg = "operation failed";