gpio: xilinx: Find out bank before use in xilinx_gpio_get_function()

Call xilinx_gpio_get_bank_pin() before use.

Reported-by: Stefan Herbrechtsmeier <stefan@herbrechtsmeier.net>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Stefan Herbrechtsmeier <stefan@herbrechtsmeier.net>
diff --git a/drivers/gpio/xilinx_gpio.c b/drivers/gpio/xilinx_gpio.c
index 48b52c9..8ce08d8 100644
--- a/drivers/gpio/xilinx_gpio.c
+++ b/drivers/gpio/xilinx_gpio.c
@@ -435,6 +435,10 @@
 	int val, ret;
 	u32 bank, pin;
 
+	ret = xilinx_gpio_get_bank_pin(offset, &bank, &pin, dev);
+	if (ret)
+		return ret;
+
 	/* Check if all pins are inputs */
 	if (platdata->bank_input[bank])
 		return GPIOF_INPUT;
@@ -443,10 +447,6 @@
 	if (platdata->bank_output[bank])
 		return GPIOF_OUTPUT;
 
-	ret = xilinx_gpio_get_bank_pin(offset, &bank, &pin, dev);
-	if (ret)
-		return ret;
-
 	/* FIXME test on dual */
 	val = readl(&platdata->regs->gpiodir + bank * 2);
 	val = !(val & (1 << pin));