This patch corrects a incorrect type conversion during encoding and
decoding the length for VARCHAR fields.


sql/log_event.cc:
  WL#3228 (NDB) : RBR using different table defs on slave/master
  
  This patch changes the encoding of the 16-bit length value for
  VARCHAR field correcting an undetected type conflict.
sql/rpl_utility.h:
  WL#3228 (NDB) : RBR using different table defs on slave/master
  
  This patch changes the decoding of the 16-bit length value for
  VARCHAR field correcting an undetected type conflict.