cmVSSetupHelper: Use in-class member initialization

Source/cmVSSetupHelper.h

@@ -107,16 +107,11 @@ struct VSInstanceInfo
   std::wstring InstanceId;
   std::wstring VSInstallLocation;
   std::wstring Version;
-  ULONGLONG ullVersion;
-  bool IsWin10SDKInstalled;
-  bool IsWin81SDKInstalled;
+  ULONGLONG ullVersion = 0;
+  bool IsWin10SDKInstalled = false;
+  bool IsWin81SDKInstalled = false;
 
-  VSInstanceInfo()
-  {
-    InstanceId = VSInstallLocation = Version = L"";
-    ullVersion = 0;
-    IsWin10SDKInstalled = IsWin81SDKInstalled = false;
-  }
+  VSInstanceInfo() = default;
 
   std::string GetInstallLocation() const;
 };