Delete redundant call to ServiceProcess::Teardown.

Currently Teardown is called twice on shutdown.

The ServiceProcess is on the stack. It will call Teardown from its
destructor when ServiceProcessMain returns.

It looks like this redundancy has been there since the service process was first introduced in:
https://codereview.chromium.org/2001009/

Review URL: https://codereview.chromium.org/1242873004

Cr-Commit-Position: refs/heads/master@{#339707}

chrome/service/service_main.cc

@@ -42,6 +42,5 @@ int ServiceProcessMain(const content::MainFunctionParams& parameters) {
   } else {
     LOG(ERROR) << "Service process failed to initialize";
   }
-  service_process.Teardown();
   return 0;
 }