selftests/bpf: Use connect_to_addr in cls_redirect

This patch uses public helper connect_to_addr() exported in
network_helpers.h instead of the local defined function connect_to_server()
in prog_tests/cls_redirect.c. This can avoid duplicate code.
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Link: https://lore.kernel.org/r/4a03ac92d2d392f8721f398fa449a83ac75577bc.1713427236.git.tanggeliang@kylinos.cnSigned-off-by: Martin KaFai Lau <martin.lau@kernel.org>

tools/testing/selftests/bpf/prog_tests/cls_redirect.c

@@ -36,22 +36,6 @@ struct tuple {
 	struct addr_port dst;
 };
 
-static int connect_to_server(const struct sockaddr *addr, socklen_t len,
-			     int type)
-{
-	int fd = socket(addr->sa_family, type, 0);
-	if (CHECK_FAIL(fd == -1))
-		return -1;
-	if (CHECK_FAIL(connect(fd, addr, len)))
-		goto err;
-
-	return fd;
-
-err:
-	close(fd);
-	return -1;
-}
-
 static bool fill_addr_port(const struct sockaddr *sa, struct addr_port *ap)
 {
 	const struct sockaddr_in6 *in6;
@@ -89,7 +73,7 @@ static bool set_up_conn(const struct sockaddr *addr, socklen_t len, int type,
 	if (CHECK_FAIL(getsockname(*server, sa, &slen)))
 		goto close_server;
 
-	*conn = connect_to_server(sa, slen, type);
+	*conn = connect_to_addr(type, (struct sockaddr_storage *)sa, slen, NULL);
 	if (*conn < 0)
 		goto close_server;