avoid parsing InformationBuffer unless status is "success"

avoid parsing InformationBuffer unless status is "success"

The MBIM specification requires that the InformationBuffer
is empty unless the status field is MBIM_STATUS_SUCCESS,
except for 4 explicit combinations of status code and
command id.

Avoid calling the reply handler if the status code is
non-zero and the information buffer is empty.

Signed-off-by: Bjørn Mork <bjorn@mork.no>