FROMGIT: f2fs: set default valid_thresh_ratio to 80 for zoned devices

Zoned storage devices provide marginal over-capacity space, typically
around 10%, for filesystem level storage control.

By utilizing this extra capacity, we can safely reduce the default
'valid_thresh_ratio' to 80. This action helps to significantly prevent
excessive garbage collection (GC) and the resulting power consumption,
as the filesystem becomes less aggressive about cleaning segments
that still hold a high percentage of valid data.

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
(cherry picked from commit 9a25aeb2be7a268c671cdf9ecc43c4a00b710af5 https://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs.git dev)
Link: https://lore.kernel.org/linux-f2fs-devel/20251003224917.1950708-1-daeho43@gmail.com



Bug: 438700991
Bug: 452922640
Change-Id: I9b40eafdcb62d4df76cef39f739decd6f159fa99
Signed-off-by: Daeho Jeong <daehojeong@google.com>
(cherry picked from commit 6c8b014d)