annotate poll_table_struct ->_key

Only POLL... bitmaps ever end up there and their only use is checking
for POLL... bits in them.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/linux/poll.h b/include/linux/poll.h
index d384f12..8927e22 100644
--- a/include/linux/poll.h
+++ b/include/linux/poll.h
@@ -37,7 +37,7 @@ typedef void (*poll_queue_proc)(struct file *, wait_queue_head_t *, struct poll_
  */
 typedef struct poll_table_struct {
 	poll_queue_proc _qproc;
-	unsigned long _key;
+	__poll_t _key;
 } poll_table;
 
 static inline void poll_wait(struct file * filp, wait_queue_head_t * wait_address, poll_table *p)
@@ -62,15 +62,15 @@ static inline bool poll_does_not_wait(const poll_table *p)
  * to be started implicitly on poll(). You typically only want to do that
  * if the application is actually polling for POLLIN and/or POLLOUT.
  */
-static inline unsigned long poll_requested_events(const poll_table *p)
+static inline __poll_t poll_requested_events(const poll_table *p)
 {
-	return p ? p->_key : ~0UL;
+	return p ? p->_key : ~(__poll_t)0;
 }
 
 static inline void init_poll_funcptr(poll_table *pt, poll_queue_proc qproc)
 {
 	pt->_qproc = qproc;
-	pt->_key   = ~0UL; /* all events enabled */
+	pt->_key   = ~(__poll_t)0; /* all events enabled */
 }
 
 struct poll_table_entry {