RDMA/siw: Remove rcu from siw_qp

Remove it since it is not used.
Acked-by: Bernard Metzler <bmt@zurich.ibm.com>
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Link: https://lore.kernel.org/r/20231113115726.12762-6-guoqing.jiang@linux.devSigned-off-by: Leon Romanovsky <leon@kernel.org>

drivers/infiniband/sw/siw/siw.h

@@ -465,7 +465,6 @@ struct siw_qp {
 	} term_info;
 	struct rdma_user_mmap_entry *sq_entry; /* mmap info for SQE array */
 	struct rdma_user_mmap_entry *rq_entry; /* mmap info for RQE array */
-	struct rcu_head rcu;
 };
 
 /* helper macros */