mtd: rawnand: Use kzalloc() instead of kmalloc() and memset()

Replace kmalloc() by a memset() followed with a kzalloc().

There is a recommendation to use zeroing allocator
rather than allocator followed by memset(0) in
./scripts/coccinelle/api/alloc/zalloc-simple.cocci
Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

drivers/mtd/nand/raw/nand_bch.c

@@ -170,7 +170,7 @@ struct nand_bch_control *nand_bch_init(struct mtd_info *mtd)
 		goto fail;
 	}
 
-	nbc->eccmask = kmalloc(eccbytes, GFP_KERNEL);
+	nbc->eccmask = kzalloc(eccbytes, GFP_KERNEL);
 	nbc->errloc = kmalloc_array(t, sizeof(*nbc->errloc), GFP_KERNEL);
 	if (!nbc->eccmask || !nbc->errloc)
 		goto fail;
@@ -182,7 +182,6 @@ struct nand_bch_control *nand_bch_init(struct mtd_info *mtd)
 		goto fail;
 
 	memset(erased_page, 0xff, eccsize);
-	memset(nbc->eccmask, 0, eccbytes);
 	encode_bch(nbc->bch, erased_page, eccsize, nbc->eccmask);
 	kfree(erased_page);