IB/hfi1: Add RcvShortLengthErrCnt to hfi1stats

This counter, RxShrErr, is required for error analysis and debug.

Fixes: 77241056 ("IB/hfi1: add driver files")
Link: https://lore.kernel.org/r/20200106134235.119356.29123.stgit@awfm-01.aw.intel.com


Reviewed-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>