FieldDef: Fix type @param fields in class javadoc

Change-Id: I9c0e9795f639b007e880871e32667b32a6ae8236
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/index/FieldDef.java b/gerrit-server/src/main/java/com/google/gerrit/server/index/FieldDef.java
index f40f534..59d3711 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/index/FieldDef.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/index/FieldDef.java
@@ -24,9 +24,9 @@
 /**
  * Definition of a field stored in the secondary index.
  *
- * @param I input type from which documents are created and search results are
+ * @param <I> input type from which documents are created and search results are
  *     returned.
- * @param T type that should be extracted from the input object when converting
+ * @param <T> type that should be extracted from the input object when converting
  *     to an index document.
  */
 public abstract class FieldDef<I, T> {