net: annotate ->poll() instances

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

net/sctp/socket.c

@@ -7497,11 +7497,11 @@ out:
  * here, again, by modeling the current TCP/UDP code.  We don't have
  * a good way to test with it yet.
  */
-unsigned int sctp_poll(struct file *file, struct socket *sock, poll_table *wait)
+__poll_t sctp_poll(struct file *file, struct socket *sock, poll_table *wait)
 {
 	struct sock *sk = sock->sk;
 	struct sctp_sock *sp = sctp_sk(sk);
-	unsigned int mask;
+	__poll_t mask;
 
 	poll_wait(file, sk_sleep(sk), wait);