prepend 'inputs.' to --test output check

agent/agent.go

@@ -209,7 +209,7 @@ func (a *Agent) Test() error {
 		// Special instructions for some inputs. cpu, for example, needs to be
 		// run twice in order to return cpu usage percentages.
 		switch input.Name() {
-		case "cpu", "mongodb", "procstat":
+		case "inputs.cpu", "inputs.mongodb", "inputs.procstat":
 			time.Sleep(500 * time.Millisecond)
 			fmt.Printf("* Plugin: %s, Collection 2\n", input.Name())
 			if err := input.Input.Gather(acc); err != nil {