btrfs: consolidate uuid comparisons in btrfs_validate_super
There are three ways the fsid is validated in btrfs_validate_super():
- verify that super_copy::fsid is the same as fs_devices::fsid
- if the metadata_uuid flag is set, verify if super_copy::metadata_uuid
and fs_devices::metadata_uuid are the same.
- a few lines below, often missed out, verify if dev_item::fsid is the
same as fs_devices::metadata_uuid.
The function btrfs_validate_super() contains multiple if-statements with
memcmp() to check UUIDs. This patch consolidates them into a single
location.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>