MFC r250371

s/Numer/Number/
MFC: 233569

Fix crash on VirtualBox (and probably on some real hardware):

- Do not cover error returned by pmc_core_initialize with the
  result of pmc_uncore_initialize, fail right away.
- Give a user something to report instead failing silently.

Submitted by:	gonzo
Reported by:	Alexandr Kovalenko <never@nevermind.kiev.ua>
Approved by:	sbruno (mentor)