Input: psmouse - wheel mice (imps, exps) always have 3rd button

There are wheel mice that respond to Logitech probes and report
that they have only 2 buttons (such as e-Aser mouse) and this
stops the wheel from being used as a middle button. Change the
driver to always report BTN_MIDDLE capability if a wheel is
present.

Also, never reset BTN_RIGHT capability in logips2pp code - there
are no Logitech mice that have only one button and if some other
mice happen to respond to Logitech's query we could do the wrong
thing.
Signed-off-by: Vojtech Pavlik <vojtech@suse.cz>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/mouse/logips2pp.c

@@ -385,8 +385,6 @@ int ps2pp_init(struct psmouse *psmouse, int set_properties)
 
 		if (buttons < 3)
 			clear_bit(BTN_MIDDLE, psmouse->dev.keybit);
-		if (buttons < 2)
-			clear_bit(BTN_RIGHT, psmouse->dev.keybit);
 
 		if (model_info)
 			ps2pp_set_model_properties(psmouse, model_info, use_ps2pp);

drivers/input/mouse/psmouse-base.c

@@ -344,6 +344,7 @@ static int intellimouse_detect(struct psmouse *psmouse, int set_properties)
 		return -1;
 
 	if (set_properties) {
+		set_bit(BTN_MIDDLE, psmouse->dev.keybit);
 		set_bit(REL_WHEEL, psmouse->dev.relbit);
 
 		if (!psmouse->vendor) psmouse->vendor = "Generic";
@@ -376,6 +377,7 @@ static int im_explorer_detect(struct psmouse *psmouse, int set_properties)
 		return -1;
 
 	if (set_properties) {
+		set_bit(BTN_MIDDLE, psmouse->dev.keybit);
 		set_bit(REL_WHEEL, psmouse->dev.relbit);
 		set_bit(BTN_SIDE, psmouse->dev.keybit);
 		set_bit(BTN_EXTRA, psmouse->dev.keybit);