pinctrl: ti-iodelay: remove redundant pin < 0 check on unsigned int

pin is an unsigned int and therefore can never be < 0 so
this check is redundant. Remove the check and the associated
dev_err error message.

Fixes CoverityScan CID#1396438 ("Unsigned compared against 0")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/ti/pinctrl-ti-iodelay.c

@@ -665,12 +665,6 @@ static void ti_iodelay_pin_dbg_show(struct pinctrl_dev *pctldev,
 	r = iod->reg_data;
 
 	offset = ti_iodelay_pin_to_offset(iod, pin);
-	if (pin < 0) {
-		dev_err(iod->dev, "invalid pin offset for pin%i\n", pin);
-
-		return;
-	}
-
 	pd = &iod->pa[pin];
 	cfg = pd->drv_data;