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

dlls/fltlib/Makefile.in

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

dlls/fltlib/fltlib.c

@@ -25,25 +25,6 @@
 
 WINE_DEFAULT_DEBUG_CHANNEL(fltlib);
 
-/*****************************************************
- *      DllMain
- */
-BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
-{
-    TRACE("(0x%p, %d, %p)\n", hinstDLL, fdwReason, lpvReserved);
-
-    switch (fdwReason)
-    {
-        case DLL_WINE_PREATTACH:
-            return FALSE;    /* use native version */
-
-        case DLL_PROCESS_ATTACH:
-            DisableThreadLibraryCalls(hinstDLL);
-            break;
-    }
-    return TRUE;
-}
-
 /**********************************************************************
  *      FilterConnectCommunicationPort         (FLTLIB.@)
  */