Restoring MSR values should be best effort.
Restoring MSR values should be best effort.

- The existing restore logic will try to restore all valid controls
  based on the msr_*.cpp at the end of a run.
- This is a problem because some sysadmins have manually adjusted their
  msr-safe whitelist files from the default on GitHub.
- The solution was to add a try/catch around the restore logic.

Change-Id: Ie1a532f9de021d2527a0e41726d400fd0d750ba5
Signed-off-by: Brad Geltz <e42f3ad4099980ea02f08e076efbee5cf9d4a803@intel.com>

cmcantalupo/geopm,cmcantalupo/geopm,geopm/geopm,cmcantalupo/geopm,geopm/geopm,geopm/geopm,geopm/geopm,cmcantalupo/geopm,cmcantalupo/geopm,geopm/geopm