libxtables: prefix/order - libdir

Consolidate the libdir variable initialization code into xtables.c.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
diff --git a/ip6tables-restore.c b/ip6tables-restore.c
index 097711f..6be1a36 100644
--- a/ip6tables-restore.c
+++ b/ip6tables-restore.c
@@ -130,16 +130,7 @@
 	program_version = XTABLES_VERSION;
 	line = 0;
 
-	lib_dir = getenv("XTABLES_LIBDIR");
-	if (lib_dir == NULL) {
-		lib_dir = getenv("IP6TABLES_LIB_DIR");
-		if (lib_dir != NULL)
-			fprintf(stderr, "IP6TABLES_LIB_DIR is deprecated, "
-			        "use XTABLES_LIBDIR.\n");
-	}
-	if (lib_dir == NULL)
-		lib_dir = XTABLES_LIBDIR;
-
+	xtables_init();
 #ifdef NO_SHARED_LIBS
 	init_extensions();
 #endif