Red Hat: use repoquery to find kernels in build script

Red Hat: use repoquery to find kernels in build script

Remove the custom yum Python code in favor of repoquery.

Reviewed-on: http://gerrit.openafs.org/4926
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>
(cherry picked from commit 1accef4e77c8cad518d728d15fbd194bebd49f33)

Change-Id: Ie68a006852d1564fa2da226a006a4e137d7cd5ed
Reviewed-on: http://gerrit.openafs.org/4979
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>