RDMA/core: Remove refcount from struct ib_mad_snoop_private

The member is never used, delete it.
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/core/mad_priv.h

@@ -115,7 +115,6 @@ struct ib_mad_snoop_private {
 	struct ib_mad_qp_info *qp_info;
 	int snoop_index;
 	int mad_snoop_flags;
-	atomic_t refcount;
 	struct completion comp;
 };