V1->V2: Change way of testing suggested by Dave Chinner
1. Create image file with FS on it
2. Call fstrim to discard free blocks
3. Check that every punched hole in the image file is in the area
that is marked as free
Signed-off-by: Tomas Racek <tracek@redhat.com>
Reviewed-by: Rich Johnston <rjohnston@sgi.com>
Signed-off-by: Rich Johnston <rjohnston@sgi.com>