sched: core: Disable double lock/unlock balance in move_queued_task()

CONFIG_LOCK_STAT shows warnings in move_queued_task() for releasing a
pinned lock. The warnings are due to the calls to
double_unlock_balance() added to snapshot WALT. Lets disable them if
not building with SCHED_WALT.

Bug: 123720375
Change-Id: I8bff8550c4f79ca535556f6ec626f17ff5fce637
Signed-off-by: Miguel de Dios <migueldedios@google.com>