get rid of the size argument of sock_sendmsg()

it's equal to iov_iter_count(&msg->msg_iter) in all cases

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/linux/net.h b/include/linux/net.h
index e74114b..738ea48 100644
--- a/include/linux/net.h
+++ b/include/linux/net.h
@@ -211,7 +211,7 @@
 int sock_create_kern(int family, int type, int proto, struct socket **res);
 int sock_create_lite(int family, int type, int proto, struct socket **res);
 void sock_release(struct socket *sock);
-int sock_sendmsg(struct socket *sock, struct msghdr *msg, size_t len);
+int sock_sendmsg(struct socket *sock, struct msghdr *msg);
 int sock_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
 		 int flags);
 struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname);