net: don't OOPS on socket aio

commit 06539d30 upstream.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

net/socket.c

@@ -887,9 +887,6 @@ static ssize_t sock_splice_read(struct file *file, loff_t *ppos,
 static struct sock_iocb *alloc_sock_iocb(struct kiocb *iocb,
 					 struct sock_iocb *siocb)
 {
-	if (!is_sync_kiocb(iocb))
-		BUG();
-
 	siocb->kiocb = iocb;
 	iocb->private = siocb;
 	return siocb;