Add missing fail() invocation

Added missing fail() call-out in the versatile flow objective handler in
OFDPA2Pipeline.java to cover the case when neither a nextId nor a
treatment is provided.

Change-Id: Ic73e614c141281ff0014a8055d35183b7c3abd4e
diff --git a/drivers/default/src/main/java/org/onosproject/driver/pipeline/OFDPA2Pipeline.java b/drivers/default/src/main/java/org/onosproject/driver/pipeline/OFDPA2Pipeline.java
index 2f58bfb..9f52ac0 100644
--- a/drivers/default/src/main/java/org/onosproject/driver/pipeline/OFDPA2Pipeline.java
+++ b/drivers/default/src/main/java/org/onosproject/driver/pipeline/OFDPA2Pipeline.java
@@ -645,6 +645,7 @@
         if (fwd.nextId() == null && fwd.treatment() == null) {
             log.error("Forwarding objective {} from {} must contain "
                     + "nextId or Treatment", fwd.selector(), fwd.appId());
+            fail(fwd, ObjectiveError.BADPARAMS);
             return Collections.emptySet();
         }