RegTest: Build fix

src/duckstation-regtest/regtest_host.cpp

@@ -99,7 +99,7 @@ bool RegTestHost::InitializeConfig()
   si.SetStringValue("MemoryCards", "Card1Type", Settings::GetMemoryCardTypeName(MemoryCardType::NonPersistent));
   si.SetStringValue("MemoryCards", "Card2Type", Settings::GetMemoryCardTypeName(MemoryCardType::None));
   si.SetStringValue("ControllerPorts", "MultitapMode", Settings::GetMultitapModeName(MultitapMode::Disabled));
-  si.SetStringValue("Audio", "Backend", Settings::GetAudioBackendName(AudioBackend::Null));
+  si.SetStringValue("Audio", "Backend", AudioStream::GetBackendName(AudioBackend::Null));
   si.SetBoolValue("Logging", "LogToConsole", true);
   si.SetBoolValue("Main", "ApplyGameSettings", false); // don't want game settings interfering
   si.SetBoolValue("BIOS", "PatchFastBoot", true);      // no point validating the bios intro..