mshtml: Avoid obj to iface cast in ProtocolFactory_Create.

dlls/mshtml/protocol.c

diff --git a/dlls/mshtml/protocol.c b/dlls/mshtml/protocol.c
index 6fdcfd3..f0325bf 100644
--- a/dlls/mshtml/protocol.c
+++ b/dlls/mshtml/protocol.c
@@ -1037,5 +1037,5 @@
         return CLASS_E_CLASSNOTAVAILABLE;
     }
  
-    return IUnknown_QueryInterface((IUnknown*)cf, riid, ppv);
+    return IInternetProtocolInfo_QueryInterface(&cf->IInternetProtocolInfo_iface, riid, ppv);
 }