locking/lockdep: Replace snprintf with strscpy in seq_stats

Replace snprintf("%s", ...) with the faster and more direct strscpy().

Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Boqun Feng <boqun@kernel.org>
Link: https://patch.msgid.link/20260318001426.2664-3-thorsten.blum@linux.dev