Return early when the value is null to reduce the depth of indents

Change-Id: I34b01d1888884ee752655d2b2bed1f6facb0b432

@@ -51,6 +51,7 @@ import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 
 import java.io.IOException;
+import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.ArrayList;
@@ -291,12 +292,15 @@ public class OFOpticalSwitchImplLINC13
     }
 
     private List<OFAction> buildActions(List<OFInstruction> iList, CircuitSignalID sigid) {
-        List<OFAction> actions = new ArrayList<>();
         Map<OFInstructionType, OFInstruction> instructions = iList.stream()
                 .collect(Collectors.toMap(OFInstruction::getType, inst -> inst));
 
         OFInstruction inst = instructions.get(OFInstructionType.APPLY_ACTIONS);
-        if (inst != null) {
+        if (inst == null) {
+            return Collections.emptyList();
+        }
+
+        List<OFAction> actions = new ArrayList<>();
         OFInstructionApplyActions iaa = (OFInstructionApplyActions) inst;
         if (iaa.getActions() == null) {
             return actions;
@@ -313,7 +317,6 @@ public class OFOpticalSwitchImplLINC13
                 actions.add(action);
             }
         });
-        }
         return actions;
     }