dmaengine: qcom_hidma: Remove call to memset after dmam_alloc_coherent

In commit 518a2f19
("dma-mapping: zero memory returned from dma_alloc_*"),
dma_alloc_coherent has already zeroed the memory.
So memset is not needed.

Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
Acked-by: Sinan Kaya <okaya@kernel.org>
Link: https://lore.kernel.org/r/20190715031723.6375-1-huangfq.daxian@gmail.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>