Append .dll extension in all cases (spotted by Mike Hearn).

[wine] / dlls / dinput / dinput.spec

@ stdcall DirectInputCreateA(long long ptr ptr)
@ stdcall DirectInputCreateW(long long ptr ptr)
@ stdcall DirectInputCreateEx(long long ptr ptr ptr)
@ stdcall -private DllCanUnloadNow() DINPUT_DllCanUnloadNow
@ stdcall -private DllGetClassObject(ptr ptr ptr) DINPUT_DllGetClassObject
@ stdcall -private DllRegisterServer() DINPUT_DllRegisterServer
@ stdcall -private DllUnregisterServer() DINPUT_DllUnregisterServer