serial: vt8500_serial: Convert to devm_ioremap_resource()

Use the newly introduced devm_ioremap_resource() instead of
devm_request_and_ioremap() which provides more consistent error handling.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Acked-by: Tony Prisk <linux@prisktech.co.nz>
Reviewed-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/vt8500_serial.c

@@ -35,6 +35,7 @@
 #include <linux/clk.h>
 #include <linux/platform_device.h>
 #include <linux/of.h>
+#include <linux/err.h>
 
 /*
  * UART Register offsets
@@ -585,9 +586,9 @@ static int vt8500_serial_probe(struct platform_device *pdev)
 	if (!vt8500_port)
 		return -ENOMEM;
 
-	vt8500_port->uart.membase = devm_request_and_ioremap(&pdev->dev, mmres);
-	if (!vt8500_port->uart.membase)
-		return -EADDRNOTAVAIL;
+	vt8500_port->uart.membase = devm_ioremap_resource(&pdev->dev, mmres);
+	if (IS_ERR(vt8500_port->uart.membase))
+		return PTR_ERR(vt8500_port->uart.membase);
 
 	vt8500_port->clk = of_clk_get(pdev->dev.of_node, 0);
 	if (IS_ERR(vt8500_port->clk)) {