svcrdma: Drop connection after an RDMA Read error

When an RPC Call message cannot be pulled from the client, that
is a message loss, by definition. Close the connection to trigger
the client to resend.

Cc: <stable@vger.kernel.org>
Reviewed-by: Tom Talpey <tom@talpey.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

net/sunrpc/xprtrdma/svc_rdma_recvfrom.c

@@ -852,7 +852,8 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp)
 	if (ret == -EINVAL)
 		svc_rdma_send_error(rdma_xprt, ctxt, ret);
 	svc_rdma_recv_ctxt_put(rdma_xprt, ctxt);
-	return ret;
+	svc_xprt_deferred_close(xprt);
+	return -ENOTCONN;
 
 out_backchannel:
 	svc_rdma_handle_bc_reply(rqstp, ctxt);