fanotify: Make waits for fanotify events only killable

Making waits for response to fanotify permission events interruptible
can result in EINTR returns from open(2) or other syscalls when there's
e.g. AV software that's monitoring the file. Orion reports that e.g.
bash is complaining like:

bash: /etc/bash_completion.d/itweb-settings.bash: Interrupted system call

So for now convert the wait from interruptible to only killable one.
That is mostly invisible to userspace. Sadly this breaks hibernation
with fanotify permission events pending again but we have to put more
thought into how to fix this without regressing userspace visible
behavior.

Reported-by: Orion Poplawski <orion@nwra.com>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index ff7b8a1..6b9c275 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -92,8 +92,8 @@
 
 	pr_debug("%s: group=%p event=%p\n", __func__, group, event);
 
-	ret = wait_event_interruptible(group->fanotify_data.access_waitq,
-				       event->state == FAN_EVENT_ANSWERED);
+	ret = wait_event_killable(group->fanotify_data.access_waitq,
+				  event->state == FAN_EVENT_ANSWERED);
 	/* Signal pending? */
 	if (ret < 0) {
 		spin_lock(&group->notification_lock);