Avoid a memset after a call to 'dma_alloc_coherent()'.
This is useless since
commit 518a2f19 ("dma-mapping: zero memory returned from dma_alloc_*")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>