Revert "futex: Avoid taking hb lock if nothing to wakeup"

This reverts commit 5551ddc31f857870c8417749fd518b4773ef9dec.
Revert "futex: Document ordering guarantees"

This reverts commit f95ec674faa56122e5024bf8fa2979f17d79ec41.
Revert "futex: Larger hash table"

This reverts commit ccb5ae8ad2aeb3f2b8038ac57b06a532e906bf88.
Revert "futex: Misc cleanups"

This reverts commit cbfa2751c2dbcd4f1dd2d518f2fff53201c03400.
config: Disable f2fs for now.