change format of 'last LU seen'

So far, the time string format comes from ctime_r, and we manually add "UTC" to it.

The ctime_r format is wildly chaotic IMHO, mixing weekday, day-of-month and
hour and year in very unsorted ways.

Adding "UTC" to it is non-standard.

Instead use an ISO-8601 standardized time string via strftime().

Change-Id: I6731968f05050399f4dd43b241290186e0c59e1a
1 file changed