Input: logips2pp - ignore mice reporting model as 0

There are mice reporting to logitech's queries with model
of 0. Do not claim that these are Logitech mice.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/mouse/logips2pp.c

@@ -338,12 +338,12 @@ int ps2pp_init(struct psmouse *psmouse, int set_properties)
 	param[1] = 0;
 	ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO);
 
-	if (!param[1])
-		return -1;
-
 	model = ((param[0] >> 4) & 0x07) | ((param[0] << 3) & 0x78);
 	buttons = param[1];
 
+	if (!model || !buttons)
+		return -1;
+
 	if ((model_info = get_model_info(model)) != NULL) {
 
 /*