[PATCH] xfstests: handle new mkfs.btrfs -f option cleanly

[Rich Johnston]

Looks good.

Reviewed-by: Rich Johnston <rjohnston at sgi.com>

This patch has been committed.

Thanks
--Rich

commit 24fef70ef3fa0be047264b7a40b0bcf86533ec22
Author: Eric Sandeen <sandeen at redhat.com>
Date:   Tue Feb 26 20:42:38 2013 +0000

     xfstests: handle new mkfs.btrfs -f option cleanly

     I added an "-f" option to mkfs.btrfs to force overwrite
     of an existing filesystem.  Now on an xfstests run, new
     mkfs.btrfs requires it, and old mkfs.btrfs cannot accept
     it.

     So, add a helper which works out whether -f is needed,
     and add it to the MKFS_BTRFS_PROG env. var as necessary,
     so that it is an always-included option during the tests.

     Signed-off-by: Eric Sandeen <sandeen at redhat.com>
     Reviewed-by: Rich Johnston <rjohnston at sgi.com>
     Signed-off-by: Rich Johnston <rjohnston at sgi.com>