SUNRPC: Fix xs_setup_bc_tcp()

It is a BUG for anybody to call this function without setting
args->bc_xprt. Trying to return an error value is just wrong, since the
user cannot fix this: it is a programming error, not a user error.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

net/sunrpc/xprtsock.c

@@ -2442,9 +2442,6 @@ static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
 	struct sock_xprt *transport;
 	struct svc_sock *bc_sock;
 
-	if (!args->bc_xprt)
-		ERR_PTR(-EINVAL);
-
 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries);
 	if (IS_ERR(xprt))
 		return xprt;