f2fs: don't drop compressed page cache in .{invalidate,release}page

For compressed inode, in .{invalidate,release}page, we will call
f2fs_invalidate_compress_pages() to drop all compressed page cache of
current inode.

But we don't need to drop compressed page cache synchronously in
.invalidatepage, because, all trancation paths of compressed physical
block has been covered with f2fs_invalidate_compress_page().

And also we don't need to drop compressed page cache synchronously
in .releasepage, because, if there is out-of-memory, we can count
on page cache reclaim on sbi->compress_inode.

BTW, this patch may fix the issue reported below:

https://lore.kernel.org/linux-f2fs-devel/20211202092812.197647-1-changfengnan@vivo.com/T/#u



Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>