Revert "futex: Always cleanup owner tid in unlock_pi"

This reverts commit a80d4bcf67b2fc6cc36e4007c23c62f32d726087.
Revert "futex: Validate atomic acquisition in futex_lock_pi_atomic()"

This reverts commit e319f33f82a82a0f23e784c9784873d71dba0873.
Revert "futex: uninitialized warning corrections"

This reverts commit 81323a7aee3299506a2fc2758fa1955645e85f72.