Issue #16384: avoid lspci warnings on OpenVZ containers

I did not dare to shuffle things around in the huge _virtual() method.
Instead, logging gets postponed, and upon detection of 'virtual:openvzve',
failures for lspci and dmidecode get discarded
Replace backslash-quote with raw string formatting
Merge pull request #16387 from terminalmage/bp-16386

Backport #16386 to 2014.7