netfilter: nft_extdhr: Drop pointless check of tprot_set

Pablo says, tprot_set is only there to detect if tprot was set to
IPPROTO_IP as that evaluates to zero. Therefore, code asserting a
different value in tprot does not need to check tprot_set.

Fixes: 935b7f64 ("netfilter: nft_exthdr: add TCP option matching")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nft_exthdr.c

@@ -164,7 +164,7 @@ nft_tcp_header_pointer(const struct nft_pktinfo *pkt,
 {
 	struct tcphdr *tcph;
 
-	if (!pkt->tprot_set || pkt->tprot != IPPROTO_TCP)
+	if (pkt->tprot != IPPROTO_TCP)
 		return NULL;
 
 	tcph = skb_header_pointer(pkt->skb, nft_thoff(pkt), sizeof(*tcph), buffer);