IB/rdmavt: Fix send scheduling

call_send is used to determine whether to send immediately or schedule
a send for later. The current logic in rdmavt is inverted and has a
negative impact on the latency of the hfi1 and qib drivers. Fix this
regression by correctly calling send immediately when call_send is set.

Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Jubin John <jubin.john@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>