btrfs: drop unused parameter file_offset from btrfs_encoded_read_regular_fill_pages()

btrfs: drop unused parameter file_offset from btrfs_encoded_read_regular_fill_pages()

[ Upstream commit 590168edbe6317ca9f4066215fb099f43ffe745c ]

The file_offset parameter used to be passed to encoded read struct but
was removed in commit b665affe93d8 ("btrfs: remove unused members from
struct btrfs_encoded_read_private").

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 05b36b04d74a ("btrfs: fix use-after-free in btrfs_encoded_read_endio()")
Signed-off-by: Sasha Levin <sashal@kernel.org>