selftests/net: add tls to .gitignore

Add the tls binary to .gitignore

Fixes: 7f657d5b ("selftests: tls: add selftests for TLS sockets")
Signed-off-by: NAnders Roxell <anders.roxell@linaro.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tools/testing/selftests/net/.gitignore

@@ -13,3 +13,4 @@ udpgso
 udpgso_bench_rx
 udpgso_bench_tx
 tcp_inq
+tls