dmaengine: idxd: No need to clear memory after a dma_alloc_coherent() call

dma_alloc_coherent() already clear the allocated memory, there is no need
to explicitly call memset().

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/f44be04317387f8936d31d5470963541615f30ef.1685283065.git.christophe.jaillet@wanadoo.fr


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