anntotate the places where ->poll() return values go

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/net/socket.c b/net/socket.c
index 42d8e9c..dceab22 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1093,7 +1093,7 @@ EXPORT_SYMBOL(sock_create_lite);
 /* No kernel lock held - perfect */
 static unsigned int sock_poll(struct file *file, poll_table *wait)
 {
-	unsigned int busy_flag = 0;
+	__poll_t busy_flag = 0;
 	struct socket *sock;
 
 	/*