RDMA/verbs: Remove restrack entry from XRCD structure

XRCD object is not implemented in the restrack, so lets remove it.

Fixes: 02d8883f520e ("RDMA/restrack: Add general infrastructure to track RDMA resources")
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

include/rdma/ib_verbs.h

@@ -1537,10 +1537,6 @@ struct ib_xrcd {
 
 	struct mutex		tgt_qp_mutex;
 	struct list_head	tgt_qp_list;
-	/*
-	 * Implementation details of the RDMA core, don't use in drivers:
-	 */
-	struct rdma_restrack_entry res;
 };
 
 struct ib_ah {