tty: audit: Fix audit source

The data to audit/record is in the 'from' buffer (ie., the input
read buffer).

Fixes: 72586c6061ab ("n_tty: Fix auditing support for cannonical mode")
Cc: stable <stable@vger.kernel.org> # 4.1+
Cc: Miloslav Trmač <mitr@redhat.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Acked-by: Laura Abbott <labbott@fedoraproject.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 1384426..ed77614 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -169,7 +169,7 @@
 {
 	struct n_tty_data *ldata = tty->disc_data;
 
-	tty_audit_add_data(tty, to, n, ldata->icanon);
+	tty_audit_add_data(tty, from, n, ldata->icanon);
 	return copy_to_user(to, from, n);
 }