tcpx_listen: tcp_newtcpcb doesn't fail

Signed-off-by: Doug Evans <dje@google.com>
diff --git a/src/socket.c b/src/socket.c
index 679ac4f..fc64b8f 100644
--- a/src/socket.c
+++ b/src/socket.c
@@ -763,10 +763,7 @@
     so = socreate(slirp);
 
     /* Don't tcp_attach... we don't need so_snd nor so_rcv */
-    if ((so->so_tcpcb = tcp_newtcpcb(so)) == NULL) {
-        g_free(so);
-        return NULL;
-    }
+    so->so_tcpcb = tcp_newtcpcb(so);
     insque(so, &slirp->tcb);
 
     /*