Enable checkstyle Javadoc Comment Style rule

Turn on the Javadoc Comment Style rule and fix
any violations that come up.  This is related to
requiring javadoc description comments to end
with a '.'

Change-Id: I19cf1b9f00d3040987e0b4c8b39461e2e0ad66b5
diff --git a/src/main/java/net/onrc/onos/core/devicemanager/IOnosDeviceService.java b/src/main/java/net/onrc/onos/core/devicemanager/IOnosDeviceService.java
index 9eb6e31..e0ab4f6 100644
--- a/src/main/java/net/onrc/onos/core/devicemanager/IOnosDeviceService.java
+++ b/src/main/java/net/onrc/onos/core/devicemanager/IOnosDeviceService.java
@@ -6,7 +6,7 @@
 /**
  * {@link OnosDeviceManager} doesn't yet provide any API to fellow modules,
  * however making it export a dummy service means we can specify it as
- * a dependency of Forwarding
+ * a dependency of Forwarding.
  *
  * @author jono
  */