zram: rename writeback_compressed device attr

zram: rename writeback_compressed device attr

Rename writeback_compressed attr to compressed_writeback to avoid possible
confusion and have more natural naming.  writeback_compressed may look
like an alternative version of writeback while in fact
writeback_compressed only sets a writeback property.  Make this
distinction more clear with a new compressed_writeback name.

This updates a feature which is new in 7.0-rcX.

Link: https://lkml.kernel.org/r/20260226025429.1042083-1-senozhatsky@chromium.org
Fixes: 4c1d61389e8e ("zram: introduce writeback_compressed device attribute")
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Suggested-by: Minchan Kim <minchan@kernel.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Richard Chang <richardycc@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: "Christoph Böhmwalder" <christoph.boehmwalder@linbit.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lars Ellenberg <lars.ellenberg@linbit.com>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>