docs: corrected comment to talk about Ref

Author: theburningmonk

lib/deploy/stepFunctions/compileIamRole.js

@@ -180,7 +180,7 @@ function getLambdaPermissions(state) {
     }];
   } else if (_.has(functionName, 'Ref')) {
     // because the FunctionName parameter can be either a name or ARN
-    // so you should be able to use Fn::GetAtt here to get the ARN
+    // so you should be able to use Ref here to get the function name
     return [{
       action: 'lambda:InvokeFunction',
       resource: {