fs: seq_file - add event counter to simplify poll() support

Moving the event counter into the dynamically allocated 'struc seq_file'
allows poll() support without the need to allocate its own tracking
structure.

All current users are switched over to use the new counter.

Requested-by: Andrew Morton akpm@linux-foundation.org
Acked-by: NeilBrown <neilb@suse.de>
Tested-by: Lucas De Marchi lucas.demarchi@profusion.mobi
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/namespace.c b/fs/namespace.c
index fe59bd1..cda50fe 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -934,8 +934,8 @@
 	int res = 0;
 
 	br_read_lock(vfsmount_lock);
-	if (p->event != ns->event) {
-		p->event = ns->event;
+	if (p->m.poll_event != ns->event) {
+		p->m.poll_event = ns->event;
 		res = 1;
 	}
 	br_read_unlock(vfsmount_lock);