itss: Return S_FALSE in IStream::Read if there is no more data to read.
diff --git a/dlls/itss/storage.c b/dlls/itss/storage.c
index d2e346c..9d1b343 100644
--- a/dlls/itss/storage.c
+++ b/dlls/itss/storage.c
@@ -660,7 +660,7 @@
     if( pcbRead )
         *pcbRead = count;
     
-    return S_OK;
+    return count ? S_OK : S_FALSE;
 }
 
 static HRESULT WINAPI ITSS_IStream_Write(