nvflinger: Change log message in OpenDisplay to be a debug log instead of a warning

Opening a display isn't really a thing to warn about. It's an expected
thing, so this can be a debug log. This also alters the string to
indicate the display name better.

Opening "Default" display reads a little nicer compared to Opening
display Default.

src/core/hle/service/nvflinger/nvflinger.cpp

@@ -47,7 +47,7 @@ void NVFlinger::SetNVDrvInstance(std::shared_ptr<Nvidia::Module> instance) {
 }
 
 u64 NVFlinger::OpenDisplay(std::string_view name) {
-    LOG_WARNING(Service, "Opening display {}", name);
+    LOG_DEBUG(Service, "Opening \"{}\" display", name);
 
     // TODO(Subv): Currently we only support the Default display.
     ASSERT(name == "Default");