Revert "binder: fix max_thread type inconsistency"

This reverts commit ddbcd7d3 which is
commit 42316941 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
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Carlos Llamas <cmllamas@google.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Change-Id: Iebcf9735dfca88b314736860f13c1fc66f4b7c67
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>