Merge pull request #1620 from devoncarew/ios_output

remove an extraneous line of output when launching the simulator

packages/flutter_tools/lib/src/ios/device_ios.dart

@@ -476,7 +476,7 @@ class IOSSimulator extends Device {
     }
 
     // Step 4: Launch the updated application in the simulator
-    int launchResult = await runCommandAndStreamOutput([
+    runCheckedSync([
       xcrunPath,
       'simctl',
       'launch',
@@ -484,11 +484,6 @@ class IOSSimulator extends Device {
       app.id
     ]);
 
-    if (launchResult != 0) {
-      printError('Could not launch the freshly installed application on the simulator');
-      return false;
-    }
-
     printTrace('Successfully started ${app.name} on $id');
     return true;
   }