Fix Sonar warnings about NPEs after an exception

Change-Id: Ic6ddfe4cef6a1e1df32b896a2dfdbc6053d0a4eb
diff --git a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/cli/OpenstackAddAclCommand.java b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/cli/OpenstackAddAclCommand.java
index 9610603..1b9a707 100644
--- a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/cli/OpenstackAddAclCommand.java
+++ b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/cli/OpenstackAddAclCommand.java
@@ -76,6 +76,7 @@
             dstIpAddress = IpAddress.valueOf(dstIpStr);
         } catch (IllegalArgumentException e) {
             log.error("IllegalArgumentException occurred because of {}", e.toString());
+            return;
         }
 
         TrafficSelector.Builder sBuilder = DefaultTrafficSelector.builder()
diff --git a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/cli/OpenstackRemoveAclCommand.java b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/cli/OpenstackRemoveAclCommand.java
index 47dc137..cba0c7a 100644
--- a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/cli/OpenstackRemoveAclCommand.java
+++ b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/cli/OpenstackRemoveAclCommand.java
@@ -73,6 +73,7 @@
             dstIpAddress = IpAddress.valueOf(dstIpStr);
         } catch (IllegalArgumentException e) {
             log.error("IllegalArgumentException occurred because of {}", e.toString());
+            return;
         }
 
         TrafficSelector.Builder sBuilder = DefaultTrafficSelector.builder()