xprtrdma: Clean up rpcrdma_ia_open()

Untangle the end of rpcrdma_ia_open() by moving DMA MR set-up, which
is different for each registration method, to the .ro_open functions.

This is refactoring only. No behavior change is expected.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Devesh Sharma <devesh.sharma@avagotech.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index ce4e79e..8219011 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -65,9 +65,8 @@
 	struct ib_device	*ri_device;
 	struct rdma_cm_id 	*ri_id;
 	struct ib_pd		*ri_pd;
-	struct ib_mr		*ri_bind_mem;
+	struct ib_mr		*ri_dma_mr;
 	u32			ri_dma_lkey;
-	int			ri_have_dma_lkey;
 	struct completion	ri_done;
 	int			ri_async_rc;
 	unsigned int		ri_max_frmr_depth;