RDMA/rxe: Simplify cq->notify code

RDMA/rxe: Simplify cq->notify code

The flags parameter to the request notify verb is a bitmask. But, rxe
driver treats cq->notify as an int. If someone ever set both the
IB_CQ_SOLICITED and the IB_CQ_NEXT_COMP bits rxe_cq_post could fail to
generate a completion event. This patch treats the notify flags as a bit
mask consistently and can handle the above case correctly.

Link: https://lore.kernel.org/r/20230612162244.20038-1-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>