RegionEvent: fix documentation

Description for REGION_REMOVED and REGION_UPDATED were mistakenly
switched.

Change-Id: I7b4dcb19980c47f544693d207ea12cf6ffd75e42
diff --git a/core/api/src/main/java/org/onosproject/net/region/RegionEvent.java b/core/api/src/main/java/org/onosproject/net/region/RegionEvent.java
index 4a399bc..8dad91b 100644
--- a/core/api/src/main/java/org/onosproject/net/region/RegionEvent.java
+++ b/core/api/src/main/java/org/onosproject/net/region/RegionEvent.java
@@ -36,12 +36,12 @@
         REGION_ADDED,
 
         /**
-         * Signifies that a region was updated.
+         * Signifies that a region was removed.
          */
         REGION_REMOVED,
 
         /**
-         * Signifies that a region was removed.
+         * Signifies that a region was updated.
          */
         REGION_UPDATED,