use function-wide declaration also for loop body.


ndb/src/kernel/blocks/dbdict/Dbdict.cpp:
  Get rid of a duplicate declaration ('Uint32 k;' at function start) that caused 
  compiler failures on 'octane2' (both 32 and 64 bit) and a compiler crash on 'ds20'.
  It would be better not to use those variable declarations with a loop scope,
  they have caused compile problems again and again.