Revert "sbitmap: fix io hung due to race on sbitmap_word::cleared"

This reverts commit 8fe6e8cb which is
commit 72d04bdc 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: If3218a950ccffbc0ba1834ab4803448267e88eda
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>