crypto: starfive - Skip dma setup for zeroed message

Skip dma setup and mapping for AES driver if plaintext is empty.

Signed-off-by: Jia Jie Ho <[e-mail]>
Signed-off-by: Herbert Xu <[e-mail]>

drivers/crypto/starfive/jh7110-aes.c

···
 	if (ret)
 		return ret;
 
+	if (!cryp->total_in)
+		goto finish_req;
+
 	starfive_aes_dma_init(cryp);
 
 	ret = starfive_aes_map_sg(cryp, rctx->in_sg, rctx->out_sg);
 	if (ret)
 		return ret;
 
+finish_req:
 	starfive_aes_finish_req(ctx);
 
 	return 0;