x86/crypto: fix scatterwalk_unmap issue in cis sm4 driver

Signed-off-by: yangdepei <yangdepei@hygon.cn>
Signed-off-by: Wentao Guan <guanwentao@uniontech.com>

Author: yangdepei

arch/x86/crypto/sm4_cis_glue.c

@@ -773,13 +773,12 @@ static int sm4_gcm_do_crypt(struct aead_request *req, bool encrypt)
 		if (zfilled)
 			crypto_shash_update(cis_ctx->ghash_desc, pad, zfilled);
 
+		if (!assocmem)
+			scatterwalk_unmap(assoc);
+		else
+			kfree(assocmem);
 	}
 
-	if (!assocmem)
-		scatterwalk_unmap(assoc);
-	else
-		kfree(assocmem);
-
 	err = encrypt ? skcipher_walk_aead_encrypt(&walk, req, false)
 		  : skcipher_walk_aead_decrypt(&walk, req, false);
 	if (err)