drivers/dma: drop unnecesary memset

memset of 0 is not needed after kzalloc

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

// <smpl>
@@
expression x;
statement S;
@@

x = kzalloc(...);
if (x == NULL) S
... when != x
-memset(x,0,...);// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

drivers/dma/dw_dmac.c

@@ -1270,8 +1270,6 @@ static int __init dw_probe(struct platform_device *pdev)
 		goto err_kfree;
 	}
 
-	memset(dw, 0, sizeof *dw);
-
 	dw->regs = ioremap(io->start, DW_REGLEN);
 	if (!dw->regs) {
 		err = -ENOMEM;