staging/rdma/hfi1: Fix memory leaks

Fix 3 memory leaks reported by the LeakCheck tool in the KEDR framework.

The following resources were allocated memory during their respective
initializations but not freed during cleanup:
1. SDMA map elements
2. PIO map elements
3. HW send context to SW index map

This patch fixes the memory leaks by freeing the allocated memory in the
cleanup path.

Reviewed-by: Dean Luick <dean.luick@intel.com>
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>