IB/mad: Fix compare between big endian and cpu endian

The define OPA_LID_PERMISSIVE is big endian and was compared to the
cpu endian variable opa_drslid.

Problem caught by 0-day build infrastructure.

Fixes: 8e4349d1 (IB/mad: Add final OPA MAD processing)
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Reviewed-by: John, Jubin <jubin.john@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>