usb: host: xhci-mem: remove unneeded break

A break is not needed if it is preceded by a return.

Signed-off-by: Tom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/20201026185812.1427461-1-trix@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>