IPoIB/cm: Fix receive QP cleanup

Commit 1b524963 ("IPoIB/cm: Use common CQ for CM send completions")
changed how the high-order bits of work request IDs were used, which
had the effect that IPOIB_CM_RX_DRAIN_WRID was no longer handled as a
connected mode receive completion.  This leads to the messages

    ib1: cm send completion event with wrid 1073741823 (> 64)
    ib1: RX drain timing out

when an interface with connected mode QPs is brought down.  Fix this
by making sure that both IPOIB_OP_CM and IPOIB_OP_RECV are set in
IPOIB_CM_RX_DRAIN_WRID.

Signed-off-by: Roland Dreier <rolandd@cisco.com>