Xext: pass the current screen to miProcessDeviceEvent() from xtest calls

Not passing in a screen means we skip the screen crossing updates, so a
xtest event that changes between ScreenRecs won't do so until the next
physical event comes in or never, whichever comes earlier.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Keith Packard <keithp@keithp.com>

Xext/xtest.c

@@ -418,7 +418,7 @@ ProcXTestFakeInput(ClientPtr client)
     }
 
     for (i = 0; i < nevents; i++)
-        mieqProcessDeviceEvent(dev, &xtest_evlist[i], NULL);
+        mieqProcessDeviceEvent(dev, &xtest_evlist[i], miPointerGetScreen(inputInfo.pointer));
 
     if (need_ptr_update)
         miPointerUpdateSprite(dev);