cgroup/pids: Remove superfluous zeroing

Atomic counters are in kzalloc'd struct. They are zeroed already and
atomic64_t does not need special initialization
(cf kernel/trace/trace_clock.c:trace_counter).
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

kernel/cgroup/pids.c

@@ -75,9 +75,7 @@ pids_css_alloc(struct cgroup_subsys_state *parent)
 	if (!pids)
 		return ERR_PTR(-ENOMEM);
 
-	atomic64_set(&pids->counter, 0);
 	atomic64_set(&pids->limit, PIDS_MAX);
-	atomic64_set(&pids->events_limit, 0);
 	return &pids->css;
 }