abis_nm: Mark the structs as extern to avoid compiler warning
warning: array ‘abis_nm_obj_class_names’ assumed to have one element
diff --git a/include/osmocom/gsm/abis_nm.h b/include/osmocom/gsm/abis_nm.h
index e7c3769..720b603 100644
--- a/include/osmocom/gsm/abis_nm.h
+++ b/include/osmocom/gsm/abis_nm.h
@@ -9,8 +9,8 @@
const enum abis_nm_msgtype abis_nm_sw_load_msgs[9];
const enum abis_nm_msgtype abis_nm_nacks[33];
-const struct value_string abis_nm_obj_class_names[];
-const struct value_string abis_nm_adm_state_names[];
+extern const struct value_string abis_nm_obj_class_names[];
+extern const struct value_string abis_nm_adm_state_names[];
const char *abis_nm_nack_cause_name(uint8_t cause);
const char *abis_nm_nack_name(uint8_t nack);