start: Use standard va_list instead of __ms_va_list.

programs/start/start.c

@@ -77,7 +77,7 @@ static void fatal_error(const WCHAR *msg, DWORD error_code, const WCHAR *filenam
     output(L": ");
     args[0] = (DWORD_PTR)filename;
     status = FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ARGUMENT_ARRAY,
-                            NULL, error_code, 0, (LPWSTR)&lpMsgBuf, 0, (__ms_va_list *)args );
+                            NULL, error_code, 0, (LPWSTR)&lpMsgBuf, 0, (va_list *)args );
     if (!status)
     {
         WINE_ERR("FormatMessage failed\n");