misc: Use static const struct for LAPD and Abis
diff --git a/src/gsm/abis_nm.c b/src/gsm/abis_nm.c
index f6d4003..f3f3a42 100644
--- a/src/gsm/abis_nm.c
+++ b/src/gsm/abis_nm.c
@@ -380,7 +380,7 @@
 	return get_value_string(avail_names, avail);
 }
 
-static struct value_string test_names[] = {
+static const struct value_string test_names[] = {
 	/* FIXME: standard test names */
 	{ NM_IPACC_TESTNO_CHAN_USAGE, "Channel Usage" },
 	{ NM_IPACC_TESTNO_BCCH_CHAN_USAGE, "BCCH Channel Usage" },