fix: gprs_gmm, gprs_llc_vty: two unterminated value_string arrays

Change-Id: Icc4163ac4f962fe88bbebeb3310a557ba0834e84
diff --git a/openbsc/src/gprs/gprs_llc_vty.c b/openbsc/src/gprs/gprs_llc_vty.c
index e97416b..bf34e97 100644
--- a/openbsc/src/gprs/gprs_llc_vty.c
+++ b/openbsc/src/gprs/gprs_llc_vty.c
@@ -48,6 +48,7 @@
 	{ GPRS_LLES_ABM,		"Asynchronous Balanced Mode" },
 	{ GPRS_LLES_LOCAL_REL,		"Local Release" },
 	{ GPRS_LLES_TIMER_REC,		"Timer Recovery" },
+	{ 0, NULL }
 };
 
 static void vty_dump_lle(struct vty *vty, struct gprs_llc_lle *lle)