btrfs: drop unused parameter options from open_ctree()

[ Upstream commit 87cbab86 ]

Since the new mount option parser in commit ad21f15b ("btrfs:
switch to the new mount API") we don't pass the options like that
anymore.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 951a3f59 ("btrfs: fix mount failure due to remount races")
Signed-off-by: Sasha Levin <sashal@kernel.org>