* Fix cases where a CPU ucode version is not found in $procfs/cpuinfo.
When running whithin a virtual machine, it seems like $procfs/cpuinfo doesn't contain
a 'microcode' line, which triggers a script runtime error.
Fall back to '0x0' in this case, as other part of the script seems to already this
as a default value anyway.
* Double quote to prevent globbing and word splitting.
