This patch removes the remaining on-stack buffer for USB DMA transfer.
This patch also reduces the stack memory usage.

Cc: stable@kernel.org
Cc: Florian Mickler <florian@mickler.org>
Signed-off-by: NOlivier Grenie <olivier.grenie@dibcom.fr>
Signed-off-by: NPatrick Boettcher <patrick.boettcher@dibcom.fr>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>