Staging: rtl8723bs: Use kzfree rather than its implementation

Use kzfree instead of memset() + kfree().
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Link: https://lore.kernel.org/r/1567566079-7412-4-git-send-email-zhongjiang@huawei.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8723bs/core/rtw_security.c

@@ -2290,8 +2290,7 @@ static void gf_mulx(u8 *pad)
 
 static void aes_encrypt_deinit(void *ctx)
 {
-	memset(ctx, 0, AES_PRIV_SIZE);
-	kfree(ctx);
+	kzfree(ctx);
 }