erofs: avoid tagged pointers to mark sync decompression

erofs: avoid tagged pointers to mark sync decompression

[ Upstream commit cdba55067f2f9fdc7870ffcb6aef912d3468cff8 ]

We could just use a boolean in z_erofs_decompressqueue for sync
decompression to simplify the code.

Reviewed-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20230204093040.97967-2-hsiangkao@linux.alibaba.com
Stable-dep-of: 967c28b23f6c ("erofs: kill hooked chains to avoid loops on deduplicated compressed images")
Signed-off-by: Sasha Levin <sashal@kernel.org>