[MODIFICATION] Un-do `fixfiles` Workaround In The `PostBuild.sh` Script

[ferricoxide]

Is your feature request related to a problem? Please describe.

Previously, the fixfiles invocation in the PostBuild.sh script was failing due to the selinux-policy RPM's %post script failing to place some necessary files into the build-target disk. Had opened an issue with Red Hat about this in May of this year. It appears that, the workaround has been obviated. May as well remove it from the code-base.

Describe the solution you'd like

Remove lines 417 through 426 from PostBuild.sh script.