HID: uhid: Fix returning EPOLLOUT from uhid_char_poll

Always return EPOLLOUT from uhid_char_poll to allow polling /dev/uhid
for writable state.

Fixes: 1f9dec1e ("HID: uhid: allow poll()'ing on uhid devices")
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/uhid.c

@@ -772,7 +772,7 @@ static __poll_t uhid_char_poll(struct file *file, poll_table *wait)
 	if (uhid->head != uhid->tail)
 		return EPOLLIN | EPOLLRDNORM;
 
-	return 0;
+	return EPOLLOUT | EPOLLWRNORM;
 }
 
 static const struct file_operations uhid_fops = {