ext2: remove redundant building macro check

If macro CONFIG_QUOTA is not enabled then mount option flag
of usrquota/grpquota will not be set, so we can remove some
building macro check safely in ext2_shwo_options().
Additionally, I think it's better to define EXT2_MOUNT_DAX
regardless macro CONFIG_FS_DAX is enabled just like acl/xattr.

Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Signed-off-by: Jan Kara <jack@suse.cz>