drm/tinydrm: Use kmemdup rather than duplicating its implementation in repaper_spi_transfer()

use kmemdup rather than duplicating its implementation

Signed-off-by: YueHaibing <[e-mail]>
Signed-off-by: Noralf Trønnes <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/tinydrm/repaper.c

···
 
 	/* Stack allocated tx? */
 	if (tx && len <= 32) {
-		txbuf = kmalloc(len, GFP_KERNEL);
+		txbuf = kmemdup(tx, len, GFP_KERNEL);
 		if (!txbuf) {
 			ret = -ENOMEM;
 			goto out_free;
 		}
-		memcpy(txbuf, tx, len);
 	}
 
 	if (rx) {