btrfs/220: fix clear_cache and inode_cache option tests

btrfs/220: fix clear_cache and inode_cache option tests

I recently changed clear_cache to not appear in mount options, as it
has one shot semantics, which was breaking this test. Test
explicitly that it _doesn't_ appear, which properly fails on old
filesystems and passes on misc-next.

The patch that changed this behavior was:
8b228324a8ce btrfs: clear free space tree on ro->rw remount

Separately, inode_cache is deprecated and will never appear in mount
options; remove it entirely.

Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>