system: mark tunnel_attr_list as extern

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

diff --git a/system.h b/system.h
index b3298bd..97fbc8b 100644 (file)
--- a/system.h
+++ b/system.h
@@ -37,7 +37,7 @@ enum tunnel_param {
        __TUNNEL_ATTR_MAX
 };
 
-const struct uci_blob_param_list tunnel_attr_list;
+extern const struct uci_blob_param_list tunnel_attr_list;
 
 enum bridge_opt {
        /* stp and forward delay always set */