test: dm: eth: Skip timeouts on ping tests

Indicate to the emulated sandbox Ethernet driver when we expect a
timeout and tell it to leap forward.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/test/dm/eth.c b/test/dm/eth.c
index 4891f3a..196eba8 100644
--- a/test/dm/eth.c
+++ b/test/dm/eth.c
@@ -135,6 +135,7 @@
 	sandbox_eth_disable_response(1, true);
 	setenv("ethact", "eth@10004000");
 	setenv("netretry", "yes");
+	sandbox_eth_skip_timeout();
 	ut_assertok(net_loop(PING));
 	ut_asserteq_str("eth@10002000", getenv("ethact"));
 
@@ -144,6 +145,7 @@
 	 */
 	setenv("ethact", "eth@10004000");
 	setenv("netretry", "no");
+	sandbox_eth_skip_timeout();
 	ut_asserteq(-ETIMEDOUT, net_loop(PING));
 	ut_asserteq_str("eth@10004000", getenv("ethact"));