src: add xfree and use it

This patch adds xfree, a replacement of free that accepts
const pointers. This helps to remove ugly castings that you usually
need to calm down gcc.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/expr.c b/src/expr.c
index 84fd64b..1f33181 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -49,7 +49,7 @@ EXPORT_SYMBOL(nft_rule_expr_alloc);
 
 void nft_rule_expr_free(struct nft_rule_expr *expr)
 {
-	free(expr);
+	xfree(expr);
 }
 EXPORT_SYMBOL(nft_rule_expr_free);