fix javadoc lint error

pom.xml

-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>com.xeiam.xchart</groupId>
@@ -135,6 +136,7 @@
 				</executions>
 				<configuration>
 					<excludePackageNames>com.xeiam.xchart.internal.*</excludePackageNames>
+					<additionalparam>-Xdoclint:none</additionalparam>
 				</configuration>
 			</plugin>
 			<plugin>