Blackfin arch: As Mike pointed out range goes form m..MAX_BLACKFIN_GPIO -1

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <michael.frysinger@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>

arch/blackfin/kernel/bfin_gpio.c

@@ -138,7 +138,7 @@ static unsigned int sic_iwr_irqs[gpio_bank(MAX_BLACKFIN_GPIOS)] = {IRQ_PROG0_INT
 
 inline int check_gpio(unsigned short gpio)
 {
-	if (gpio > MAX_BLACKFIN_GPIOS)
+	if (gpio >= MAX_BLACKFIN_GPIOS)
 		return -EINVAL;
 	return 0;
 }