usb: gadget: u_serial: Remove old tasklet comments

Update old comments as of 8b4c62ae (usb: gadget: u_serial: process RX
in workqueue instead of tasklet).
Acked-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Link: https://lore.kernel.org/r/20210119001321.127750-1-dave@stgolabs.netSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/gadget/function/u_serial.c

@@ -344,7 +344,7 @@ __acquires(&port->port_lock)
 }
 
 /*
- * RX tasklet takes data out of the RX queue and hands it up to the TTY
+ * RX work takes data out of the RX queue and hands it up to the TTY
  * layer until it refuses to take any more data (or is throttled back).
  * Then it issues reads for any further data.
  *
@@ -707,7 +707,7 @@ static void gs_close(struct tty_struct *tty, struct file *file)
 
 	/* Iff we're disconnected, there can be no I/O in flight so it's
 	 * ok to free the circular buffer; else just scrub it.  And don't
-	 * let the push tasklet fire again until we're re-opened.
+	 * let the push async work fire again until we're re-opened.
 	 */
 	if (gser == NULL)
 		kfifo_free(&port->port_write_buf);