FROMGIT: erofs: rename some generic methods in decompressor

Previously, some LZ4 methods were named with `generic'. However, while
evaluating the effective LZMA approach, it seems they aren't quite
generic at all (e.g. no need preparing dstpages for most LZMA cases.)

Avoid such naming instead.

Link: https://lore.kernel.org/r/20211010213145.17462-7-xiang@kernel.org


Acked-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
(cherry picked from commit a71118da
 https://android.googlesource.com/kernel/common

 android13-5.10)

BUG=b:273658215
TEST=`tast run $DUT arc.Boot.vm`
TEST=`tast run $DUT arc.Playstore.vm`

Change-Id: I1a8ac6a5ddf76061bd85fbb43d9f107db4b58415
Signed-off-by: Ryuichiro Chiba <chibar@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/4583886


Reviewed-by: Hikaru Nishida <hikalium@chromium.org>
Reviewed-by: Sean Paul <sean@poorly.run>