core: Silence warnings when compiling without asserts

src/core/file_sys/registered_cache.cpp

@@ -105,7 +105,8 @@ ContentRecordType GetCRTypeFromNCAType(NCAContentType type) {
         // TODO(DarkLordZach): Peek at NCA contents to differentiate Manual and Legal.
         return ContentRecordType::HtmlDocument;
     default:
-        UNREACHABLE_MSG("Invalid NCAContentType={:02X}", static_cast<u8>(type));
+        UNREACHABLE_MSG("Invalid NCAContentType={:02X}", type);
+        return ContentRecordType{};
     }
 }