Btrfs: don't bother kicking async if there's nothing to reclaim

We do this check when we start the async reclaimer thread, might as well check
before we kick it off to save us some cycles.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
1 file changed