Revert "Staging: zram: Fix access of NULL pointer"

This reverts commit 5d3f1ea528102c50de39a9bb1ad17999cfe1ef9f.
Revert "zram: allow request end to coincide with disksize"

This reverts commit 5bb64638ce0c3b16209aa6ca9ff8815fa92adfe5.
Revert "zram: avoid access beyond the zram device"

This reverts commit 3434d43a16960661920a46d469e2a90895b50b4a.
Revert "zram: destroy all devices on error recovery path in zram_init()"

This reverts commit bab785ed585c63d5eba9c94ddebf91f4b91d19d8.
Revert "zram: avoid invalid memory access in zram_exit()"

This reverts commit 5666046c5717b44bf0380c1f61a41ba66d73217b.
Revert "zram: Fix deadlock bug in partial read/write"

This reverts commit b74c4e84ccff3af13ff77b2b8c488dad99c1bbc4.
jenad: linux 3.4.92