btrfs: use test_and_set_bit() in btrfs_delayed_delete_inode_ref()

btrfs: use test_and_set_bit() in btrfs_delayed_delete_inode_ref()

Instead of testing and setting the BTRFS_DELAYED_NODE_DEL_IREF bit in the
delayed node's flags, use test_and_set_bit() which makes the code shorter
without compromising readability and getting rid of the label and goto.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Daniel Vacek <neelx@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>