Revert "fix build after latest merge"

This reverts commit 763c8afe07b4aef66172af32a3f7c979fa6190d6.
Revert "zram: don't grab mutex in zram_slot_free_noity"

This reverts commit 34131e3346a57172a132763d6a1f39b3fcb0b1b7.
Revert "staging: zram: Rate limit memory allocation errors"

This reverts commit 87b5171c53b3fec0ecfef4450b0e3e7477d555ba.
Revert "zram: Change ratio to 90% for bad compress"

This reverts commit cb7ea78aacf67f5184512489726547fccc50d125.
Revert "zram: Disable allocation failure logging"

This reverts commit 6a03aaf9bfe59e9ab0df5d7e9de7dff69c6fa366.
Revert "Staging: zram: Fix memory leak by refcount mismatch"

This reverts commit 2426b1fbd5c866280032938ec2623f7a130ae045.
Revert "Staging: zram: Fix access of NULL pointer"

This reverts commit f08850489f38ae0cf6faf3dc1a86b0d5c5a10e1d.
Revert "zram: fix invalid memory access"

This reverts commit 4cdeb35fe9c2de9af7b776318571da6395b08475.
Revert "Staging: zram: zram_drv.c: Fixed Error of trailing whitespace"

This reverts commit 7cf6182c3a3302c36b2ffae6f734216316d3bd40.
Revert "zram: prevent data loss in error cases of function zram_bvec_write()"

This reverts commit dbd1c2a04899a8af43a2b16134a4e5d963115d16.
Revert "staging: zram: protect zram_reset_device() call"

This reverts commit 844bebab848811b2c2ca62a358ecbb8cfa265283.
Revert "zram: allow request end to coincide with disksize"

This reverts commit 6e2f0210ef59d30e355a99afeb1b7f801ee7ca70.
Revert "zram: remove zram_sysfs file (v2)"

This reverts commit 0ce22e9056450ea545511953fadfd5f699c115d9.
Revert "zram: use atomic64_xxx() to replace zram_stat64_xxx()"

This reverts commit 4ab8da477e0d74bdc3cef5f4619bdc0135916bf8.
Revert "zram: optimize memory operations with clear_page()/copy_page()"

This reverts commit a0b8e9df5734bcb1409aeb16b4e4eb27e7a410b0.
Revert "zram: kill unused zram_get_num_devices()"

This reverts commit 593cc8bd5ebe4e9867eea7db5fd8248aac24c1a3.
Revert "zram: simplify and optimize dev_to_zram()"

This reverts commit f653b90d4f79a515e0383555dc96bb60448e7975.
Revert "zram: protect sysfs handler from invalid memory access"

This reverts commit 3b6791322de8dc170df74fdf812c3463705014a6.
Revert "zram: avoid access beyond the zram device"

This reverts commit 0f8257fbfc7ece00999e0a473a1571be28fd3bcb.
Revert "zram: avoid double free in function zram_bvec_write()"

This reverts commit 33b8c5cfab6328ed1c61c30e7d82861f97ced9ff.