Made some changes from review comments:

- Made LoadKernelSystemMode return a pair consisting of a system mode and a result code (Could use review).
- Deleted ErrorOpenGL error code in favor of just having ErrorVideoCore.
- Made dialog messages more clear.
- Compared archive ID in fs_user.cpp to ArchiveIdCode::NCCH as opposed to hex magic.
- Cleaned up some other stuff.

src/citra_qt/bootmanager.cpp

@@ -40,7 +40,6 @@ void EmuThread::run() {
             Core::System::ResultStatus result = Core::System::GetInstance().RunLoop();
             if (result != Core::System::ResultStatus::Success) {
                 emit ErrorThrown(result);
-                break;
             }
 
             was_active = running || exec_step;