dmaengine: rcar-dmac: drop double zeroing

sg_init_table zeroes its first argument, so the allocation of that argument
doesn't have to.

the semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression x,n,flags;
@@

x =
- kcalloc
+ kmalloc_array
  (n,sizeof(*x),flags)
...
sg_init_table(x,n)
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>

Link: https://lore.kernel.org/r/1600601186-7420-10-git-send-email-Julia.Lawall@inria.fr
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Author: JuliaLawall

drivers/dma/sh/rcar-dmac.c

@@ -1227,7 +1227,7 @@ rcar_dmac_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr,
 	 * Allocate the sg list dynamically as it would consume too much stack
 	 * space.
 	 */
-	sgl = kcalloc(sg_len, sizeof(*sgl), GFP_NOWAIT);
+	sgl = kmalloc_array(sg_len, sizeof(*sgl), GFP_NOWAIT);
 	if (!sgl)
 		return NULL;