ASoC: wm0010: Use kmemdup rather than duplicating its implementation

kmemdup is introduced to duplicate a region of memory in a neat way.
Rather than kmalloc/kzalloc + memcpy, which the programmer needs to
write the size twice (sometimes lead to mistakes), kmemdup improves
readability, leads to smaller code and also reduce the chances of mistakes.
Suggestion to use kmemdup rather than using kmalloc/kzalloc + memcpy.
Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
Acked-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20190703163224.1029-1-huangfq.daxian@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/wm0010.c

@@ -515,7 +515,7 @@ static int wm0010_stage2_load(struct snd_soc_component *component)
 	dev_dbg(component->dev, "Downloading %zu byte stage 2 loader\n", fw->size);
 
 	/* Copy to local buffer first as vmalloc causes problems for dma */
-	img = kzalloc(fw->size, GFP_KERNEL | GFP_DMA);
+	img = kmemdup(&fw->data[0], fw->size, GFP_KERNEL | GFP_DMA);
 	if (!img) {
 		ret = -ENOMEM;
 		goto abort2;
@@ -527,8 +527,6 @@ static int wm0010_stage2_load(struct snd_soc_component *component)
 		goto abort1;
 	}
 
-	memcpy(img, &fw->data[0], fw->size);
-
 	spi_message_init(&m);
 	memset(&t, 0, sizeof(t));
 	t.rx_buf = out;