Fixed typo in javadoc

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1524855 13f79535-47bb-0310-9956-ffa450edef68
Fixed typo in javadoc

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1524889 13f79535-47bb-0310-9956-ffa450edef68