staging/rdma/hfi1: Remove unnecessary parentheses

Remove unnecessary parentheses around addressof single $Lvals to fix
checkpatch check:
CHECK: Unnecessary parentheses around $var

Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@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>