Merge pull request #2157 in SNORT/snort3 from ~BBANTWAL/snort3:latency_fixes to master

Merge pull request #2157 in SNORT/snort3 from ~BBANTWAL/snort3:latency_fixes to master

Squashed commit of the following:

commit 58ed84f405600b31ff40e34e584b83ba425a5c80
Author: Bhagya Tholpady <bbantwal@cisco.com>
Date:   Wed Apr 15 10:57:44 2020 -0400

    latency: use test_timeout config option to deterministically trigger latency events for ifdef REG_TEST

commit f88468caba4dacb779eb722f0a2f706f0a9de5da
Author: Bhagya Tholpady <bbantwal@cisco.com>
Date:   Mon Apr 13 08:28:26 2020 -0400

    latency: check if ip header is present before deferring it