w1: ds2490: use kmemdup rather than duplicating its implementation

Use kmemdup rather than duplicating its implementation.

Generated by: scripts/coccinelle/api/memdup.cocci

Signed-off-by: Wei Yongjun <[e-mail]>
Acked-by: Maciej S. Szmigiero <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/w1/masters/ds2490.c

···
 	if (len <= 0)
 		return;
 
-	tbuf = kmalloc(len, GFP_KERNEL);
+	tbuf = kmemdup(buf, len, GFP_KERNEL);
 	if (!tbuf)
 		return;
 
-	memcpy(tbuf, buf, len);
 	ds_write_block(dev, tbuf, len);
 
 	kfree(tbuf);