You cannot take a DMA address, cast it to a _pointer to_ a DMA address,
and then regard it as a virtual address of the transfer buffer.
However, finding the right virtual address was too hard for me,
so I just stubbed it with NULL. At least usbmon won't oops then
(it will not show any data but it's better than crashing).
Also, too big a buffer was allocated elsewhere.
And since we're at it, drop clearly unnecessary usb_buffer_alloc too,
leaving it where it may be useful.
Signed-off-by: Pete Zaitcev <zaitcev@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>