Cleanup USB requests outside of interrupt context

From: Ross Philipson <ross.philipson@gmail.com>, Tomasz Wroblewski <tomasz.wroblewski@citrix.com>

The calls to free the USB requests in interrupt context was causing an
oops in dma_free_attrs. On x84 32b it does a WARN_ON(irqs_disabled()) "for
portability".

Signed-off-by: Ross Philipson <ross.philipson@gmail.com>
---

Tickets: OXT-28