USB: serial: use variable for status

This patch turns status in a variable read once from the URB.
The long term plan is to deliver status to the callback.
In addition it makes the code a bit more elegant.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Johan Hovold <johan@kernel.org>

drivers/usb/serial/generic.c

@@ -350,6 +350,7 @@ void usb_serial_generic_read_bulk_callback(struct urb *urb)
 	struct usb_serial_port *port = urb->context;
 	unsigned char *data = urb->transfer_buffer;
 	unsigned long flags;
+	int status = urb->status;
 	int i;
 
 	for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {
@@ -360,22 +361,22 @@ void usb_serial_generic_read_bulk_callback(struct urb *urb)
 
 	dev_dbg(&port->dev, "%s - urb %d, len %d\n", __func__, i,
 							urb->actual_length);
-	switch (urb->status) {
+	switch (status) {
 	case 0:
 		break;
 	case -ENOENT:
 	case -ECONNRESET:
 	case -ESHUTDOWN:
 		dev_dbg(&port->dev, "%s - urb stopped: %d\n",
-							__func__, urb->status);
+							__func__, status);
 		return;
 	case -EPIPE:
 		dev_err(&port->dev, "%s - urb stopped: %d\n",
-							__func__, urb->status);
+							__func__, status);
 		return;
 	default:
 		dev_dbg(&port->dev, "%s - nonzero urb status: %d\n",
-							__func__, urb->status);
+							__func__, status);
 		goto resubmit;
 	}
 
@@ -399,6 +400,7 @@ void usb_serial_generic_write_bulk_callback(struct urb *urb)
 {
 	unsigned long flags;
 	struct usb_serial_port *port = urb->context;
+	int status = urb->status;
 	int i;
 
 	for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i) {
@@ -410,22 +412,22 @@ void usb_serial_generic_write_bulk_callback(struct urb *urb)
 	set_bit(i, &port->write_urbs_free);
 	spin_unlock_irqrestore(&port->lock, flags);
 
-	switch (urb->status) {
+	switch (status) {
 	case 0:
 		break;
 	case -ENOENT:
 	case -ECONNRESET:
 	case -ESHUTDOWN:
 		dev_dbg(&port->dev, "%s - urb stopped: %d\n",
-							__func__, urb->status);
+							__func__, status);
 		return;
 	case -EPIPE:
 		dev_err_console(port, "%s - urb stopped: %d\n",
-							__func__, urb->status);
+							__func__, status);
 		return;
 	default:
 		dev_err_console(port, "%s - nonzero urb status: %d\n",
-							__func__, urb->status);
+							__func__, status);
 		goto resubmit;
 	}