Fix bug 1338614

util.log_time()'s return value was what was being sent to fork_cb. This means
the resize ran in parallel and the call to fork_cb threw a traceback (trying
to call Nonetype).

By permitting fork_cb to take kwargs, and using the correct method syntax,
this now forks and resizes in the background as appropriate.
Remove pylint: lines
merge from trunk
resizefs: fix backgrounded resizing

add kwargs to fork_cb, and utilize that to call log_time and pass through
the provided args to resize_cmd.