mi: Remove spurious call to OsReleaseSignals from mieqGrowQueue

This call wasn't converted to 'input_unlock()' when the SIGIO code was
removed from the server, and so when the queue growing was reworked to
be done from the input thread, it got left sitting here. As the caller
now manages the lock, we don't need to switch this to input_unlock at
this point.

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

mi/mieq.c

@@ -160,7 +160,6 @@ mieqGrowQueue(EventQueuePtr eventQueue, size_t new_nevents)
             for (j = 0; j < i; j++)
                 FreeEventList(new_events[j].events, 1);
             free(new_events);
-            OsReleaseSignals();
             return FALSE;
         }
         new_events[i].events = evlist;