libmsc: fix another memleak (struct gsm_sms) in gsm340_rx_tpdu()

Change-Id: I42e819fb83096c1432df16f501b9d1f6a6160ae7
Fixes: I2c50904349dd4ed229b60b8468d776b817c0bd44
diff --git a/src/libmsc/gsm_04_11.c b/src/libmsc/gsm_04_11.c
index bd7cf1f..722973e 100644
--- a/src/libmsc/gsm_04_11.c
+++ b/src/libmsc/gsm_04_11.c
@@ -642,7 +642,7 @@
 	 * attempt re-submission to the ESME)
 	 */
 	if (rc == GSM411_RP_CAUSE_MO_NET_OUT_OF_ORDER)
-		return rc;
+		goto out; /* free() the message */
 
 	/*
 	 * This SMS got routed through SMPP or no receiver exists.