i2c: ismt: 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.
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/i2c/busses/i2c-ismt.c

@@ -781,8 +781,6 @@ static int ismt_dev_init(struct ismt_priv *priv)
 	if (!priv->hw)
 		return -ENOMEM;
 
-	memset(priv->hw, 0, (ISMT_DESC_ENTRIES * sizeof(struct ismt_desc)));
-
 	priv->head = 0;
 	init_completion(&priv->cmp);