logd: deal with sloppy leading expire messages

(cherry pick from commit 5392aac9)

The odds of chatty content also leading the logs is pretty high eg:

 1799 12017 I logd: uid=10007 chatty comm=Binder_B, expire 4 lines
 1799  1829 I logd: uid=10007 chatty comm=Binder_2, expire 4 lines
 1919 20637 I logd: uid=10007 chatty comm=m.sersistent, expire 1 line
 1919 20638 I logd: uid=10007 chatty comm=s.persistent, expire 1 line
 1919  2316 I logd: uid=10007 chatty comm=UlrDispatch, expire 4 lines
19379 20634 I logd: uid=10045 chatty, expire 14 lines
19379 19388 I logd: uid=10045 chatty comm=lizerDaemon, expire 4 lines
  591  4396 I logd: uid=1000 chatty comm=Thread-220, expire 5 lines
  591  1377 I logd: uid=1000 chatty comm=Thread-92, expire 4 lines
 1919  2267 I logd: uid=10007 chatty comm=WifiScanner, expire 4 lines
  591  4397 I logd: uid=1000 chatty comm=DhcpClient, expire 4 lines
  591  4398 I logd: uid=1000 chatty comm=Thread-222, expire 4 lines
  226   580 D CommandListener: Setting iface cfg

Change-Id: I5ab24bc7bf5d2690bae7e789831b07f23ff8bcc6