sh: remove call to memset after dma_alloc_coherent

Function dma_alloc_coherent use in buf already zeroes out memory,
so memset is not needed.
Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
Signed-off-by: Rich Felker <dalias@libc.org>

arch/sh/mm/consistent.c

@@ -57,8 +57,6 @@ int __init platform_resource_setup_memory(struct platform_device *pdev,
 		return -ENOMEM;
 	}
 
-	memset(buf, 0, memsize);
-
 	r->flags = IORESOURCE_MEM;
 	r->start = dma_handle;
 	r->end = r->start + memsize - 1;