Revert "futex: Make lookup_pi_state more robust"

This reverts commit 453ac1db28b1640f59c050ef6a0650f61c3181ce.
Revert "futex: Always cleanup owner tid in unlock_pi"

This reverts commit 20ef0ab001da5451be64177045bc4b14b23f0da5.
Revert "futex: Validate atomic acquisition in futex_lock_pi_atomic()"

This reverts commit 22c9ef2cb5c0f0e89c178c4e18e264314f882899.
Revert "futex-prevent-requeue-pi-on-same-futex.patch futex: Forbid uaddr == uaddr2 in futex_requeue(..., requeue_pi=1)"

This reverts commit 278d460ffadb5d87445d89cb6c16b0f60ae7be1e.
Revert "futex: Add another early deadlock detection check"

This reverts commit 6fd7c1732d77ce1d3882f0b385da160fd0e3deba.
Revert "futex: Prevent attaching to kernel threads"

This reverts commit a3f576c9a5dd669aecf5a78eb0e5e752e2441d14.