In a couple of places we use flock for critical sections, but we leave
lockfiles around in various locations which can be confusing.
Introduce DIB_LOCKFILES global (under ~/.cache/dib/lockfiles) and
write lockfiles in there.
Fix up removal of the lockfile in the yum path; we just want to make
sure we cleanup the .rpmmacros file, but we don't need to remove the
lockfile as well.
Co-Authored-By: Andreas Florath <andreas@florath.net>
Change-Id: Ie810b2836be521325afe923708d046112e1e1e20
b25d0337b8