dix: remove now-erroneous comment about frozen slave devices.

A direct grab on a slave device through XI2 detaches it, regardless of
whether the grab is sync or async. So this comment doesn't apply to XI2
anyway.

For XI1, aside from your life being miserable already, it doesn't matter as
XI1 does not have a concept of attachment. You can freeze a device and if
you don't freeze _all_ other devices at the same time, the master device can
still happily send events to the client.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Acked-by: Adam Jackson <ajax@redhat.com>
(cherry picked from commit c0d9419131)

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

dix/events.c

@@ -1414,11 +1414,6 @@ CheckGrabForSyncs(DeviceIntPtr thisDev, Bool thisMode, Bool otherMode)
 	    thisDev->deviceGrab.sync.other = NullGrab;
     }
 
-    /*
-        XXX: Direct slave grab won't freeze the paired master device.
-        The correct thing to do would be to freeze all SDs attached to the
-        paired master device.
-     */
     if (IsMaster(thisDev))
     {
         dev = GetPairedDevice(thisDev);