telnet_init_dynif: propagate error

Return actual error from osmo_sock_init_ofd() to the caller.

Change-Id: Ib09f4315b3868ec031ecbced8a63069e7c2de7da
diff --git a/src/vty/telnet_interface.c b/src/vty/telnet_interface.c
index 132cd2e..1758860 100644
--- a/src/vty/telnet_interface.c
+++ b/src/vty/telnet_interface.c
@@ -94,7 +94,7 @@
 	if (rc < 0) {
 		LOGP(DLGLOBAL, LOGL_ERROR, "Cannot bind telnet at %s %d\n",
 		     ip, port);
-		return -1;
+		return rc;
 	}
 
 	LOGP(DLGLOBAL, LOGL_NOTICE, "Available via telnet %s %d\n", ip, port);