Fix malformed javadoc

Fix literal characters, html tags, and malformed usages.
diff --git a/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/annotations/Immutable.java b/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/annotations/Immutable.java
index 5de2171..6b0ba00 100644
--- a/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/annotations/Immutable.java
+++ b/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/annotations/Immutable.java
@@ -6,7 +6,7 @@
  * construction. Such a class can be freely shared between threads and does not
  * require defensive copying (don't call clone).
  *
- * @author Andreas Wundsam <andreas.wundsam@bigswitch.com>
+ * @author Andreas Wundsam {@literal <}andreas.wundsam@bigswitch.com{@literal >}
  */
 public @interface Immutable {