RDMA/hfi1: Delete unreachable code

All callers allocate MAD structures with proper sizes, there is no need to
recheck it.

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Leon Romanovsky <[e-mail]>
Signed-off-by: Jason Gunthorpe <[e-mail]>

drivers/infiniband/hw/hfi1/mad.c

···
 {
 	switch (in_mad->base_version) {
 	case OPA_MGMT_BASE_VERSION:
-		if (unlikely(in_mad_size != sizeof(struct opa_mad))) {
-			dev_err(ibdev->dev.parent, "invalid in_mad_size\n");
-			return IB_MAD_RESULT_FAILURE;
-		}
 		return hfi1_process_opa_mad(ibdev, mad_flags, port,
 					    in_wc, in_grh,
 					    (struct opa_mad *)in_mad,