gprs_ns2: fix memory leaks when receiving SNS or invalid packets

Change-Id: I8834d3f092e6cbe4f527e95e1eebd8133a386207
diff --git a/src/gb/gprs_ns2_vc_fsm.c b/src/gb/gprs_ns2_vc_fsm.c
index ad8d4db..a8cb570 100644
--- a/src/gb/gprs_ns2_vc_fsm.c
+++ b/src/gb/gprs_ns2_vc_fsm.c
@@ -883,7 +883,8 @@
 	default:
 		LOGPFSML(fi, LOGL_ERROR, "NSEI=%u Rx unknown NS PDU type %s\n", nsvc->nse->nsei,
 			 get_value_string(gprs_ns_pdu_strings, nsh->pdu_type));
-		return -EINVAL;
+		rc = -EINVAL;
+		break;
 	}
 
 out: