USB: serial: mos7720: Fix error code in mos7720_write()

This code should return -ENOMEM if the kmalloc() fails but instead it returns success.

---
The first error path is probably wrong as well?

drivers/usb/serial/mos7720.c
1077 /* try to find a free urb in the list */
1078 urb = NULL;
1079
1080 for (i = 0; i < NUM_URBS; ++i) {
1081 if (mos7720_port->write_urb_pool[i] &&
1082 mos7720_port->write_urb_pool[i]->status != -EINPROGRESS) {

  1083                          urb = mos7720_port->write_urb_pool[i];
  1084                          dev_dbg(&port->dev, "URB:%d\n", i);
  1085                          break;

1086 }
1087 }
1088
1089 if (urb = NULL) {
1090 dev_dbg(&port->dev, "%s - no more free urbs\n", __func__);
1091 goto exit;

Should return -ENODEV?

1092 }

 drivers/usb/serial/mos7720.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

index ed347a6d50ba..aa55169796a3 100644
@@ -1094,8 +1094,10 @@ static int mos7720_write(struct tty_struct *tty, struct usb_serial_port *port,
 	if (urb->transfer_buffer = NULL) {
 		urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE,
 					       GFP_ATOMIC);
-		if (!urb->transfer_buffer)
+		if (!urb->transfer_buffer) {
+			bytes_sent = -ENOMEM;
 			goto exit;
+		}
 	}
 	transfer_size = min(count, URB_TRANSFER_BUFFER_SIZE);
 

2.29.2

No, this bit is correct (modulo the missing locking and reliance on the URB status). When there are no free URBs we want the tty layer to retry later.