fixes issue with eos shared module argument precedence

The eos shared module should prefer to use explicit task arguments over
arguments provided through the provider.  This fixes a problem where
that was not the case

lib/ansible/module_utils/eos.py

@@ -148,7 +148,8 @@ class NetworkModule(AnsibleModule):
         provider = params.get('provider') or dict()
         for key, value in provider.items():
             if key in NET_COMMON_ARGS.keys():
-                params[key] = value
+                if not params.get(key) and value is not None:
+                    params[key] = value
         return params
 
     def connect(self):