GH-1254: Fix javadoc

Author: garyrussell

spring-kafka-test/src/main/java/org/springframework/kafka/test/EmbeddedKafkaBroker.java

@@ -231,7 +231,7 @@ public EmbeddedKafkaBroker brokerListProperty(String brokerListProperty) {
 
 	/**
 	 * Get the port that the embedded Zookeeper is running on or will run on.
-	 * @param zkPort the port.
+	 * @return the port.
 	 * @since 2.3
 	 */
 	public int getZkPort() {