Typo error in KafkaWordCount example

topicpMap to topicMap

Author: Gaspar Munoz <munozs.88@gmail.com>

Closes #2614 from gasparms/patch-1 and squashes the following commits:

00aab2c [Gaspar Munoz] Typo error in KafkaWordCount example

(cherry picked from commit b81ee0b46d63c2122b88941696654100fd736942)
Signed-off-by: Tathagata Das <tathagata.das1565@gmail.com>