lockdep_init_map() only initializes parts of lockdep_map and triggers

lockdep_init_map() only initializes parts of lockdep_map and triggers
kmemcheck warning when it is copied as a whole.  There isn't anything to
be gained by clearing selectively.  memset() the whole structure and
remove loop for ->class_cache[] clearing.

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=35532

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Christian Casteyde <casteyde.christian@free.fr>
Tested-by: Christian Casteyde <casteyde.christian@free.fr>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>