selftests/bpf: Drop duplicate bpf_map_lookup_elem in test_sockmap

bpf_map_lookup_elem is invoked in bpf_prog3() already, no need to invoke
it again. This patch drops it.
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/ea8458462b876ee445173e3effb535fd126137ed.1716446893.git.tanggeliang@kylinos.cn

tools/testing/selftests/bpf/progs/test_sockmap_kern.h

@@ -177,9 +177,6 @@ int bpf_prog3(struct __sk_buff *skb)
 		return bpf_sk_redirect_hash(skb, &tls_sock_map, &ret, flags);
 #endif
 	}
-	f = bpf_map_lookup_elem(&sock_skb_opts, &one);
-	if (f && *f)
-		ret = SK_DROP;
 	err = bpf_skb_adjust_room(skb, 4, 0, 0);
 	if (err)
 		return SK_DROP;