[patch] netfilter: nft_exthdr: fix error handling in nft_exthdr_init()

[Dan Carpenter]

"err" needs to be signed for the error handling to work.

Fixes: 36b701fae12a ('netfilter: nf_tables: validate maximum value of u32 
netlink attributes')
Signed-off-by: Dan Carpenter <dan.carpen...@oracle.com>

diff --git a/net/netfilter/nft_exthdr.c b/net/netfilter/nft_exthdr.c
index a84cf3d..47beb3a 100644
--- a/net/netfilter/nft_exthdr.c
+++ b/net/netfilter/nft_exthdr.c
@@ -59,7 +59,8 @@ static int nft_exthdr_init(const struct nft_ctx *ctx,
                           const struct nlattr * const tb[])
 {
        struct nft_exthdr *priv = nft_expr_priv(expr);
-       u32 offset, len, err;
+       u32 offset, len;
+       int err;
 
        if (tb[NFTA_EXTHDR_DREG] == NULL ||
            tb[NFTA_EXTHDR_TYPE] == NULL ||