mei: replace POLL* with EPOLL* for write queues.

Looks like during merging the bulk POLL* -> EPOLL* replacement
missed the patch
'commit af336cabe083 ("mei: limit the number of queued writes")'

Fix sparse warning:
drivers/misc/mei/main.c:602:13: warning: restricted __poll_t degrades to integer
drivers/misc/mei/main.c:605:30: warning: invalid assignment: |=
drivers/misc/mei/main.c:605:30:    left side has type restricted __poll_t
drivers/misc/mei/main.c:605:30:    right side has type int

Fixes: af336cabe083 ("mei: limit the number of queued writes")
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mei/main.c

@@ -599,10 +599,10 @@ static __poll_t mei_poll(struct file *file, poll_table *wait)
 			mei_cl_read_start(cl, mei_cl_mtu(cl), file);
 	}
 
-	if (req_events & (POLLOUT | POLLWRNORM)) {
+	if (req_events & (EPOLLOUT | EPOLLWRNORM)) {
 		poll_wait(file, &cl->tx_wait, wait);
 		if (cl->tx_cb_queued < dev->tx_queue_limit)
-			mask |= POLLOUT | POLLWRNORM;
+			mask |= EPOLLOUT | EPOLLWRNORM;
 	}
 
 out: