mshtml: Use helper for IHTMLStyle::get_height implementation.

dlls/mshtml/htmlstyle.c

@@ -2001,18 +2001,10 @@ static HRESULT WINAPI HTMLStyle_put_height(IHTMLStyle *iface, VARIANT v)
 static HRESULT WINAPI HTMLStyle_get_height(IHTMLStyle *iface, VARIANT *p)
 {
     HTMLStyle *This = impl_from_IHTMLStyle(iface);
-    BSTR ret;
-    HRESULT hres;
 
     TRACE("(%p)->(%p)\n", This, p);
 
-    hres = get_style_attr(This, STYLEID_HEIGHT, &ret);
-    if(FAILED(hres))
-        return hres;
-
-    V_VT(p) = VT_BSTR;
-    V_BSTR(p) = ret;
-    return S_OK;
+    return get_nsstyle_attr_var(This->nsstyle, STYLEID_HEIGHT, p, 0);
 }
 
 static HRESULT WINAPI HTMLStyle_put_styleFloat(IHTMLStyle *iface, BSTR v)