Merge branch 'core/locking' into perfcounters/core

Merge reason: we moved a mutex.h commit that originated from the
              perfcounters tree into core/locking - but now merge
	      back that branch to solve a merge artifact and to
	      pick up cleanups of this commit that happened in
	      core/locking.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --cc kernel/mutex.c
Simple merge