This imbalance may cause hangs when TTM is trying to swap out a buffer
that is already on the delayed delete list.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com> Reviewed-by: Jakob Bornecrantz <jakob@vmware.com> Cc: stable@vger.kernel.org Signed-off-by: Dave Airlie <airlied@redhat.com>