btrfs: remove pointless 'out' label from clone_finish_inode_update()

The label is only used once and we can instead return directly where it's
used, besides the fact that all we do under the label is to return the
value of 'ret'. So get rid of the label and return directly.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: David Sterba <dsterba@suse.com>