winex11: Only warn when an RandR output has no modes.

This can legitimately happen when the output is disconnected.

Signed-off-by: Henri Verbeet <hverbeet@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>

dlls/winex11.drv/xrandr.c

@@ -431,7 +431,7 @@ static int xrandr12_init_modes(void)
 
     if (!output_info->nmode)
     {
-        ERR("Output has no modes.\n");
+        WARN("Output has no modes.\n");
         goto done;
     }