BugLink: http://bugs.launchpad.net/bugs/1694621

commit 0377a07c upstream.

When decrementing the reference count for a block, the free count wasn't
being updated if the reference count went to zero.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>