Make kassert_printf use __printflike.

Fix associated errors/warnings while I'm here.

Requested by: avg
MFV of tzdata2013d, 253008

- Morocco:
  announced that the year's Ramadan daylight-savings transitions
  would be 2013-07-07 and 2013-08-10.

- Israel:
  As of 2013, DST starts at 02:00 on the Friday before the last
  Sunday in March.  DST ends at 02:00 on the first Sunday after
  October 1, unless it occurs on the second day of the Jewish Rosh
  Hashana holiday, in which case DST ends a day later (i.e. at 02:00
  the first Monday after October 2).  [Rosh Hashana holidays are
  factored in until 2100.]