dix: don't return BadMatch from GetProperty (#23562)

dixLookupWindow may return BadMatch if the window in question isn't actually
a window. In this case, GetProperty needs to return BadWindow - not
BadMatch.

X.Org Bug 23562 <http://bugs.freedesktop.org/show_bug.cgi?id=23562>

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

dix/property.c

@@ -474,7 +474,7 @@ ProcGetProperty(ClientPtr client)
     }
     rc = dixLookupWindow(&pWin, stuff->window, client, win_mode);
     if (rc != Success)
-	return rc;
+	return (rc == BadMatch) ? BadWindow : rc;
 
     if (!ValidAtom(stuff->property))
     {