IB/hfi1: Return SC2VL mappings to FM with VL15 instead of ILLEGAL_VL

VL15 in the SC2VL table is used to indicate an invalid SC
for the FM, however, internally the driver remaps SCs from
VL15 to ILLEGAL_VL to prevent error counts. This mapping
confuses the FM when performing a sweep, making it return
a table mismatch error. Have SMA convert ILLEGAL_VL
to VL15 entries for the SC2VL table queries.

Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Sebastian Sanchez <sebastian.sanchez@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>