Revert "perf/aux: Fix AUX buffer serialization"

This reverts commit 52d13d22 which is
commit 2ab9d830 upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: Ia2a0469ba8f50d54ced5d818f36c8d07f977f1a0
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>