gbproxy: Rename the field 'enabled_tllis' to 'logical_links'

This field in struct gbproxy_patch_state has involved and holds a
list of all tracked logical links now. Thus the name is modified
accordingly.

Sponsored-by: On-Waves ehf
diff --git a/openbsc/src/gprs/gb_proxy_peer.c b/openbsc/src/gprs/gb_proxy_peer.c
index 8f90665..ce6690e 100644
--- a/openbsc/src/gprs/gb_proxy_peer.c
+++ b/openbsc/src/gprs/gb_proxy_peer.c
@@ -163,7 +163,7 @@
 
 	llist_add(&peer->list, &cfg->bts_peers);
 
-	INIT_LLIST_HEAD(&peer->patch_state.enabled_tllis);
+	INIT_LLIST_HEAD(&peer->patch_state.logical_links);
 
 	return peer;
 }