netfilter: nf_tables: fix error return code

Author: Julia Lawall <Julia.Lawall@lip6.fr>

Convert a zero return value on error to a negative one, as returned
elsewhere in the function.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// 
@@
identifier ret; expression e1,e2;
@@
(
if (\(ret < 0\|ret != 0\))
 { ... return ret; }
|
ret = 0
)
... when != ret = e1
    when != &ret
*if(...)
{
  ... when != ret = e2
      when forall
 return ret;
}
// 

Signed-off-by: Julia Lawall 
Signed-off-by: Pablo Neira Ayuso 
---
 net/netfilter/nf_tables_api.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
 
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 9aa31f1..deeb95f 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -3137,8 +3137,10 @@ static int nft_del_setelem(struct nft_ctx *ctx, struct nft_set *set,
 		goto err2;
 
 	trans = nft_trans_elem_alloc(ctx, NFT_MSG_DELSETELEM, set);
-	if (trans == NULL)
+	if (trans == NULL) {
+		err = -ENOMEM;
 		goto err2;
+	}
 
 	nft_trans_elem(trans) = elem;
 	list_add_tail(&trans->list, &ctx->net->nft.commit_list);