Refactor the global load updates from update_shares_cpu() so that
update_cfs_load() can update global load when it is more than ~10%
out of sync.

The new global_load parameter allows us to force an update, regardless of
the error factor so that we can synchronize w/ update_shares().
Signed-off-by: NPaul Turner <pjt@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101115234938.377473595@google.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>