consistently use TEXT() macro with LoadLibrary() and GetModuleHandle()

cf. bug #5435.

src/locale/windows/SDL_syslocale.c

@@ -100,7 +100,7 @@ void
 SDL_SYS_GetPreferredLocales(char *buf, size_t buflen)
 {
     if (!kernel32) {
-        kernel32 = GetModuleHandleW(L"kernel32.dll");
+        kernel32 = GetModuleHandle(TEXT("kernel32.dll"));
         if (kernel32) {
             pGetUserPreferredUILanguages = (pfnGetUserPreferredUILanguages) GetProcAddress(kernel32, "GetUserPreferredUILanguages");
         }