Removed unused return from void method in stubs

[Vishwa4jeet]

Fixes #713

Removed unused return value for void method from generated stubs.

Screenshots:

1. Stub method generation:

   // Implementation of getServers()
   public java.util.ArrayList getServers()
           throws java.rmi.RemoteException {
       java.util.ArrayList<Object> $__params = new java.util.ArrayList<Object>();
       String $__method = "public java.util.ArrayList<amino.run.policy.Policy$ServerPolicy> amino.run.policy.DefaultPolicy$DefaultGroupPolicy.getServers() throws java.rmi.RemoteException";
       java.lang.Object $__result = null;
       try {
           $__result = $__makeKernelDMRPC($__method, $__params);
       } catch (java.rmi.RemoteException e) {
           throw e;
       } catch (java.lang.RuntimeException e) {
           throw e;
       } catch (java.lang.Exception e) {
           throw new java.lang.RuntimeException(e);
       }
       return ((java.util.ArrayList) $__result);
   }
   
   // Implementation of $__initialize(String, ArrayList)
   public void $__initialize(java.lang.String $param_String_1, java.util.ArrayList $param_ArrayList_2) {
       java.util.ArrayList<Object> $__params = new java.util.ArrayList<Object>();
       String $__method = "public void amino.run.policy.DefaultUpcallImpl$GroupPolicy.$__initialize(java.lang.String,java.util.ArrayList<java.lang.Object>)";
       $__params.add($param_String_1);
       $__params.add($param_ArrayList_2);
       try {
           $__makeKernelDMRPC($__method, $__params);
       } catch (java.lang.RuntimeException e) {
           throw e;
       } catch (java.lang.Exception e) {
           throw new java.lang.RuntimeException(e);
       }
   }

2. Proof of clean build post the change:

[quinton-hoole]

Other than trying to close issue #713, why are we doing this at all? What problem does it solve?

[VenuReddy2103]

Agreed with @quinton-hoole I understand that, we tried to remove $__result variable declaration itself if the method do not have anything to return. In fact, java.lang.Object $__result doesn't have to be explicitly initialized with null. Also these change you made are applicable for AppStub generation too(not just for policyStub). We should fix issues based on priority.