USB-Serial: Fix error handling of usb_wwan

This fixes an issue where the bulk-in urb used for incoming data transfer
is not resubmitted if the packet recieved contains an error status.  This
results in the driver locking until the port is closed and re-opened.

Tested on a custom board with a Cinterion GSM module.

Signed-off-by: Matt Burtch <matt@grid-net.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/serial/usb_wwan.c

@@ -291,18 +291,18 @@ static void usb_wwan_indat_callback(struct urb *urb)
 			tty_flip_buffer_push(&port->port);
 		} else
 			dev_dbg(dev, "%s: empty read urb received\n", __func__);
-
-		/* Resubmit urb so we continue receiving */
-		err = usb_submit_urb(urb, GFP_ATOMIC);
-		if (err) {
-			if (err != -EPERM) {
-				dev_err(dev, "%s: resubmit read urb failed. (%d)\n", __func__, err);
-				/* busy also in error unless we are killed */
-				usb_mark_last_busy(port->serial->dev);
-			}
-		} else {
+	}
+	/* Resubmit urb so we continue receiving */
+	err = usb_submit_urb(urb, GFP_ATOMIC);
+	if (err) {
+		if (err != -EPERM) {
+			dev_err(dev, "%s: resubmit read urb failed. (%d)\n",
+				__func__, err);
+			/* busy also in error unless we are killed */
 			usb_mark_last_busy(port->serial->dev);
 		}
+	} else {
+		usb_mark_last_busy(port->serial->dev);
 	}
 }