Audit: collect sessionid in netlink messages

Previously I added sessionid output to all audit messages where it was
available but we still didn't know the sessionid of the sender of
netlink messages.  This patch adds that information to netlink messages
so we can audit who sent netlink messages.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/drivers/char/tty_audit.c b/drivers/char/tty_audit.c
index 7722466..9739bbf 100644
--- a/drivers/char/tty_audit.c
+++ b/drivers/char/tty_audit.c
@@ -151,14 +151,9 @@
 /**
  *	tty_audit_push_task	-	Flush task's pending audit data
  */
-void tty_audit_push_task(struct task_struct *tsk, uid_t loginuid)
+void tty_audit_push_task(struct task_struct *tsk, uid_t loginuid, u32 sessionid)
 {
 	struct tty_audit_buf *buf;
-	/* FIXME I think this is correct.  Check against netlink once that is
-	 * I really need to read this code more closely.  But that's for
-	 * another patch.
-	 */
-	unsigned int sessionid = audit_get_sessionid(tsk);
 
 	spin_lock_irq(&tsk->sighand->siglock);
 	buf = tsk->signal->tty_audit_buf;