commit 677d23b7 upstream.

There seems to be a bad interaction between gem/shmem and defio on top,
I get list corruption on the page lru in the shmem code.

Turn it off for now until we get some more digging done.
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>