Fix test_fix_argument_yes by closing temp files
Fix test_fix_argument_yes by closing temp files

The test was randomly failing which could be caused by a race
condition - the temporary files which are created during the
test weren't closed properly which could result in a situation
when they are not yet created but the test is trying to load
them.

Closes-Bug: #1918316
Change-Id: I7a5bf8b1404dbf96955b2eb96fb1a5552760a114

openstack/tempest,openstack/tempest