d3d8: Stream indices are WORDs.

dlls/d3d8/vertexdeclaration.c

@@ -309,7 +309,7 @@ static UINT convert_to_wined3d_declaration(const DWORD *d3d8_elements, DWORD *d3
     WINED3DVERTEXELEMENT *element;
     D3DVSD_TOKENTYPE token_type;
     unsigned int element_count = 0;
-    DWORD stream = 0;
+    WORD stream = 0;
     int offset = 0;
 
     TRACE("d3d8_elements %p, wined3d_elements %p\n", d3d8_elements, wined3d_elements);