media: saa7146: 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(struct scatterlist),flags)
...
sg_init_table(x,n)
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/common/saa7146/saa7146_core.c

@@ -140,7 +140,7 @@ static struct scatterlist* vmalloc_to_sg(unsigned char *virt, int nr_pages)
 	struct page *pg;
 	int i;
 
-	sglist = kcalloc(nr_pages, sizeof(struct scatterlist), GFP_KERNEL);
+	sglist = kmalloc_array(nr_pages, sizeof(struct scatterlist), GFP_KERNEL);
 	if (NULL == sglist)
 		return NULL;
 	sg_init_table(sglist, nr_pages);