DLM: fix to reschedule rwork

When an error occurs in kernel_recvmsg or kernel_sendpage and
close_connection is called and receive work is already scheduled,
receive work is canceled. In that case, the receive work will not
be scheduled forever after reconnection, because CF_READ_PENDING
flag is established.

Signed-off-by: Tadashi Miyauchi <miyauchi@toshiba-tops.co.jp>
Signed-off-by: Tsutomu Owa <tsutomu.owa@toshiba.co.jp>
Signed-off-by: David Teigland <teigland@redhat.com>