Common/MsgHandler: Use fmt::print on non-Windows OSes

Provides the same behavior.

Source/Core/Common/MsgHandler.cpp

@@ -2,20 +2,23 @@
 // Licensed under GPLv2+
 // Refer to the license.txt file included.
 
+#include "Common/MsgHandler.h"
+
 #include <cstdarg>
-#include <cstdio>
 #include <string>
 
+#ifdef _WIN32
+#include <windows.h>
+#else
+#include <cstdio>
+#include <fmt/format.h>
+#endif
+
 #include "Common/Common.h"
 #include "Common/CommonTypes.h"
 #include "Common/Logging/Log.h"
-#include "Common/MsgHandler.h"
 #include "Common/StringUtil.h"
 
-#ifdef _WIN32
-#include <windows.h>
-#endif
-
 bool DefaultMsgHandler(const char* caption, const char* text, bool yes_no, MsgType style);
 static MsgAlertHandler msg_handler = DefaultMsgHandler;
 static bool AlertEnabled = true;
@@ -111,7 +114,7 @@ bool DefaultMsgHandler(const char* caption, const char* text, bool yes_no, MsgTy
   return IDYES == MessageBox(0, UTF8ToTStr(text).c_str(), UTF8ToTStr(caption).c_str(),
                              window_style | (yes_no ? MB_YESNO : MB_OK));
 #else
-  fprintf(stderr, "%s\n", text);
+  fmt::print(stderr, "{}\n", text);
 
   // Return no to any question (which will in general crash the emulator)
   return false;