NLS: improve UTF8 -> UTF16 string conversion routine

The utf8s_to_utf16s conversion routine needs to be improved.  Unlike
its utf16s_to_utf8s sibling, it doesn't accept arguments specifying
the maximum length of the output buffer or the endianness of its
16-bit output.

This patch (as1501) adds the two missing arguments, and adjusts the
only two places in the kernel where the function is called.  A
follow-on patch will add a third caller that does utilize the new
capabilities.

The two conversion routines are still annoyingly inconsistent in the
way they handle invalid byte combinations.  But that's a subject for a
different patch.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
kvp_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
{
	struct hv_ku_msg *message;

	message = (struct hv_ku_msg *)msg->data;
	if (msg->seq == KVP_REGISTER) {
		pr_info("KVP: user-mode registering done.\n");
		kvp_register();
	}

	if (msg->seq == KVP_USER_SET) {
		/*
		 * Complete the transaction by forwarding the key value
		 * to the host. But first, cancel the timeout.
		 */
		if (cancel_delayed_work_sync(&kvp_work))
			kvp_respond_to_host(message->kvp_key,
						message->kvp_value,
						!strlen(message->kvp_key));
	}
}

kvp_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
{
	struct hv_ku_msg *message;

	message = (struct hv_ku_msg *)msg->data;
	if (msg->seq == KVP_REGISTER) {
		pr_info("KVP: user-mode registering done.\n");
		kvp_register();
	}

	if (msg->seq == KVP_USER_SET) {
		/*
		 * Complete the transaction by forwarding the key value
		 * to the host. But first, cancel the timeout.
		 */
		if (cancel_delayed_work_sync(&kvp_work))
			kvp_respond_to_host(message->kvp_key,
						message->kvp_value,
						!strlen(message->kvp_key));
	}
}
