[vm_manager] Small changes to vm_manager.cc
[vm_manager] Small changes to vm_manager.cc

victorisildur/Graphite,mit-carbon/Graphite-Cycle-Level,mit-carbon/Graphite-Cycle-Level,8l/Graphite,8l/Graphite,nkawahara/Graphite,mit-carbon/Graphite,fhijaz/Graphite,8l/Graphite,mit-carbon/Graphite,victorisildur/Graphite,mit-carbon/Graphite-Cycle-Level,nkawahara/Graphite,fhijaz/Graphite,8l/Graphite,victorisildur/Graphite,mit-carbon/Graphite-Cycle-Level,nkawahara/Graphite,mit-carbon/Graphite,nkawahara/Graphite,victorisildur/Graphite,mit-carbon/Graphite,fhijaz/Graphite,fhijaz/Graphite