[errorprone] Fix empty javadoc block tags

See https://google.github.io/styleguide/javaguide.html#s7.1.3-javadoc-block-tags

Change-Id: I0c9ec1ecc2cd6c64a2e174ddec034e55c53ce268
diff --git a/java/com/google/gitiles/BaseServlet.java b/java/com/google/gitiles/BaseServlet.java
index e0ccce3..2aea97d 100644
--- a/java/com/google/gitiles/BaseServlet.java
+++ b/java/com/google/gitiles/BaseServlet.java
@@ -296,8 +296,8 @@
    *
    * @param req in-progress request.
    * @param res in-progress response.
-   * @param src @see com.google.gson.Gson#toJson(Object, Type, Appendable)
-   * @param typeOfSrc @see com.google.gson.Gson#toJson(Object, Type, Appendable)
+   * @param src source, @see com.google.gson.Gson#toJson(Object, Type, Appendable)
+   * @param typeOfSrc type of source, @see com.google.gson.Gson#toJson(Object, Type, Appendable)
    */
   protected void renderJson(
       HttpServletRequest req, HttpServletResponse res, Object src, Type typeOfSrc)
@@ -357,7 +357,7 @@
    * @param res in-progress response.
    * @param statusCode HTTP status code.
    * @param message full message text.
-   * @throws IOException
+   * @throws IOException if an IO error occurred.
    */
   protected void renderTextError(
       HttpServletRequest req, HttpServletResponse res, int statusCode, String message)