Update KafkaWordCount.scala

modify the required args number

Author: baishuo(白硕) <vc_java@hotmail.com>

Closes #523 from baishuo/master and squashes the following commits:

0368ba9 [baishuo(白硕)] Update KafkaWordCount.scala

(cherry picked from commit 8aaef5c75624b48806a05943454f7b72f3ca1bdc)
Signed-off-by: Tathagata Das <tathagata.das1565@gmail.com>