Btrfs: don't BUG_ON() if we get an error walking backrefs
Btrfs: don't BUG_ON() if we get an error walking backrefs

We can just return false for this so we stop doing the snapshot aware defrag
stuff.  Thanks,

Signed-off-by: Josef Bacik <631dfb3d07694fdcf26abc7aac2c6c2b641f8bde@fusionio.com>
Signed-off-by: Chris Mason <a169954b4cb1a46cee25f659d3bddfebe02b5fba@fusionio.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs