[tests] Fix Xamarin.iOS.Tasks.TargetTests.GenerateBundleName_Executab…

…leProject

msbuild has the path in it's original form (with windows slashes).

```
 Test Failure : Xamarin.iOS.Tasks.TargetTests.GenerateBundleName_ExecutableProject
     dotnet#3
  String lengths are both 42. Strings differ at index 3.
  Expected: "bin/iPhoneSimulator/Debug/MySingleView.app"
  But was:  "bin\\iPhoneSimulator\\Debug\\MySingleView.app"
  --------------^

at Xamarin.iOS.Tasks.TargetTests.GenerateBundleName_ExecutableProject () [0x00054] in /Users/ankit/dev/xamarin-macios/msbuild/tests/Xamarin.iOS.Tasks.Tests/TargetTests/TargetTests.cs:394
```

msbuild/tests/Xamarin.iOS.Tasks.Tests/TargetTests/TargetTests.cs

@@ -391,7 +391,7 @@ public void GenerateBundleName_ExecutableProject ()
 
 			// Now we should have an AppBundleDir
 			RunTargetOnInstance (MonoTouchProjectInstance, TargetName.GenerateBundleName);
-			Assert.AreEqual ("bin/iPhoneSimulator/Debug/MySingleView.app", MonoTouchProjectInstance.GetPropertyValue ("AppBundleDir"), "#3");
+			Assert.AreEqual (@"bin\iPhoneSimulator\Debug\MySingleView.app", MonoTouchProjectInstance.GetPropertyValue ("AppBundleDir"), "#3");
 		}
 
 		[Test]