The allowed value of "how" is SHUT_RD/SHUT_WR/SHUT_RDWR (0/1/2),
rather than SHUTDOWN_MASK (3).
Signed-off-by: NXi Wang <xi.wang@gmail.com>
Acked-by: NSteven Whitehouse <swhiteho@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>