commit c8648508 upstream.

On success, callback function returns 0. So invert the if condition
check so that we can break out of loop.
Signed-off-by: Ameya Palande <2ameya@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>