LatinIME: fix crash on voicetyping

on voicetyping getSuggestedWordsOrOlderSuggestionsAsync is called
as well. Due that mInputUpdater can be null on first call keyboard crashes.
Just check against null to solve it

Change-Id: Ia018fe1b774b0a67905b3e7fac941f9de7e4e8e3
Merge "LatinIME: fix crash on voicetyping" into pac-4.4