fs: annotate ->poll() instances

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c
index 9698e51..c53d9cc 100644
--- a/fs/kernfs/file.c
+++ b/fs/kernfs/file.c
@@ -832,7 +832,7 @@ void kernfs_drain_open_files(struct kernfs_node *kn)
  * to see if it supports poll (Neither 'poll' nor 'select' return
  * an appropriate error code).  When in doubt, set a suitable timeout value.
  */
-static unsigned int kernfs_fop_poll(struct file *filp, poll_table *wait)
+static __poll_t kernfs_fop_poll(struct file *filp, poll_table *wait)
 {
 	struct kernfs_open_file *of = kernfs_of(filp);
 	struct kernfs_node *kn = kernfs_dentry_node(filp->f_path.dentry);