printk: fix failure to return error in devkmsg_poll()

Error value got overwritten instantly.
Signed-off-by: Nicolas Kaiser <nikai@nikai.net>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/printk.c

@@ -601,7 +601,8 @@ static unsigned int devkmsg_poll(struct file *file, poll_table *wait)
 		/* return error when data has vanished underneath us */
 		if (user->seq < log_first_seq)
 			ret = POLLIN|POLLRDNORM|POLLERR|POLLPRI;
-		ret = POLLIN|POLLRDNORM;
+		else
+			ret = POLLIN|POLLRDNORM;
 	}
 	raw_spin_unlock_irq(&logbuf_lock);