netrom: fix copying in user data in nr_setsockopt

This code used to copy in an unsigned long worth of data before
the sockptr_t conversion, so restore that.

Fixes: a7b75c5a8c ("net: pass a sockptr_t into ->setsockopt")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/netrom/af_netrom.c

@@ -306,7 +306,7 @@ static int nr_setsockopt(struct socket *sock, int level, int optname,
 	if (optlen < sizeof(unsigned int))
 		return -EINVAL;
 
-	if (copy_from_sockptr(&opt, optval, sizeof(unsigned int)))
+	if (copy_from_sockptr(&opt, optval, sizeof(unsigned long)))
 		return -EFAULT;
 
 	switch (optname) {