RDMA/nes: Cleanup cqp_request list usage

Use nes_free_cqp_request() instead of open coding.  Change some
continue to break in nes_cm_timer_tick, because send_entry used to be
a list processed in a loop (so continue went to the next item).  Now
it is a single item, so using break is correct.

Signed-off-by: Faisal Latif <faisal.latif@intel.com>
Signed-off-by: Chien Tung <chien.tin.tung@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>