fix javadoc link

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1711957 13f79535-47bb-0310-9956-ffa450edef68

src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFCell.java

@@ -122,7 +122,7 @@ public final class XSSFCell implements Cell {
      * Copy cell value, formula, and style, from srcCell per cell copy policy
      * If srcCell is null, clears the cell value and cell style per cell copy policy
      * 
-     * This does not shift references in formulas. Use {@link XSSFRowShifter} to shift references in formulas.
+     * This does not shift references in formulas. Use {@link org.apache.poi.xssf.usermodel.helpers.XSSFRowShifter} to shift references in formulas.
      * 
      * @param srcCell
      * @param policy