Revert "usb: dwc2: host: Setting qtd to NULL after freeing it"

This reverts commit b0d659022e.

The reverted commit does nothing but adding two unnecessary lines
of code.  It sets a local variable to NULL in two functions, but
that variable is not used anywhere in the rest of those functions.
This is just confusing, so let's remove it.

Cc: Vardan Mikayelyan <mvardan@synopsys.com>
Cc: John Youn <johnyoun@synopsys.com>
Cc: Douglas Anderson <dianders@chromiun.org>
Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Minas Harutyunyan <hminas@synopsys.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc2/hcd.c

@@ -4685,7 +4685,6 @@ fail2:
 	spin_unlock_irqrestore(&hsotg->lock, flags);
 	urb->hcpriv = NULL;
 	kfree(qtd);
-	qtd = NULL;
 fail1:
 	if (qh_allocated) {
 		struct dwc2_qtd *qtd2, *qtd2_tmp;