IB/hfi1: Fix pio map initialization

The pio map initialization function is off by 1 causing the last
kernel send context that is allocated to not get mapped into the
pio map which leads to the last kernel send context not being used
by any of the qps.

The send context reserved for VL15 is taken care of by setting the
scontext variable that is used as the index into the kernel send
context array to 1 and does not need to be accounted for in the
kernel send context counting loop as it is currently done.

Fix the kernel send context counting loop to account for all the
allocated send contexts and map all of them to the different VLs.

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