misc: Use static const struct for LAPD and Abis
diff --git a/src/gsm/lapd_core.c b/src/gsm/lapd_core.c
index 96099ed..d9a1a63 100644
--- a/src/gsm/lapd_core.c
+++ b/src/gsm/lapd_core.c
@@ -2070,7 +2070,7 @@
 }
 
 /* statefull handling for DL SAP messages from L3 */
-static struct l2downstate {
+static const struct l2downstate {
 	uint32_t	states;
 	int		prim, op;
 	const char 	*name;