[PATCH] xfstests: use -F for mkfs.ext4 in btrfs/012

[Rich Johnston]

This has been committed.

Thanks
--Rich

commit 0c6fb9f3acb4bca2c4abebaf92ed5bb48472cae0
Author: Josef Bacik <jbacik at fusionio.com>
Date:   Mon Oct 21 16:05:16 2013 +0000

     xfstests: use -F for mkfs.ext4 in btrfs/012