Do not wait for sleeping in init_threads()

We can't do it with full guarantee anyway because
there is always a possible race between the setting of
state to THREAD_SLEEPING and actual sleeping.

So just remove the not perfect code to avoid misunderstandings.
This reflects what we have done in wake_sleeping_threads() in
the previous patch.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>

src/search.cpp

@@ -2768,9 +2768,6 @@ namespace {
             cout << "Failed to create thread number " << i << endl;
             Application::exit_with_failure();
         }
-
-        // Wait until the thread has finished launching and is gone to sleep
-        while (threads[i].state != THREAD_SLEEPING);
     }
   }