uiautomationcore: Use --prefer-native instead of DLL_WINE_PREATTACH.

dlls/uiautomationcore/Makefile.in

 MODULE = uiautomationcore.dll
 IMPORTLIB = uiautomationcore
 
-EXTRADLLFLAGS = -mno-cygwin
+EXTRADLLFLAGS = -mno-cygwin -Wb,--prefer-native
 
 C_SRCS = \
 	uia_main.c

dlls/uiautomationcore/uia_main.c

@@ -22,21 +22,6 @@
 
 WINE_DEFAULT_DEBUG_CHANNEL(uiautomation);
 
-BOOL WINAPI DllMain(HINSTANCE hInstDLL, DWORD fdwReason, void *lpv)
-{
-    TRACE("(%p %d %p)\n", hInstDLL, fdwReason, lpv);
-
-    switch(fdwReason) {
-    case DLL_WINE_PREATTACH:
-        return FALSE;  /* prefer native version */
-    case DLL_PROCESS_ATTACH:
-        DisableThreadLibraryCalls(hInstDLL);
-        break;
-    }
-
-    return TRUE;
-}
-
 /***********************************************************************
  *          UiaClientsAreListening (uiautomationcore.@)
  */