put iov_iter into msghdr

Note that the code _using_ ->msg_iter at that point will be very
unhappy with anything other than unshifted iovec-backed iov_iter.
We still need to convert users to proper primitives.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/net/atm/common.c b/net/atm/common.c
index f591129..b84057e 100644
--- a/net/atm/common.c
+++ b/net/atm/common.c
@@ -577,9 +577,6 @@
 	struct atm_vcc *vcc;
 	struct sk_buff *skb;
 	int eff, error;
-	struct iov_iter from;
-
-	iov_iter_init(&from, WRITE, m->msg_iov, m->msg_iovlen, size);
 
 	lock_sock(sk);
 	if (sock->state != SS_CONNECTED) {
@@ -634,7 +631,7 @@
 		goto out;
 	skb->dev = NULL; /* for paths shared with net_device interfaces */
 	ATM_SKB(skb)->atm_options = vcc->atm_options;
-	if (copy_from_iter(skb_put(skb, size), size, &from) != size) {
+	if (copy_from_iter(skb_put(skb, size), size, &m->msg_iter) != size) {
 		kfree_skb(skb);
 		error = -EFAULT;
 		goto out;