Revert "Install running kernel-devel for CentOS"
Revert "Install running kernel-devel for CentOS"

This reverts commit 569e05bb6888849d197d15424dfcbee2845fed43.  For
CentOS the running kernel may not appear in the yum repository.  Use
the latest kernel provided by the repositories, this is no longer an
issue with the TEST builders because they reboot on to the latest
kernel prior to starting the build slave.

Signed-off-by: Brian Behlendorf <32d50ad1e384dcb9a5bf7e40fa470df5dabaf348@llnl.gov>

gmelikov/zfs-buildbot,zfsonlinux/zfs-buildbot,zfsonlinux/zfs-buildbot,gmelikov/zfs-buildbot