net/netif_receive_skb_core: Use migrate_disable()

The preempt disable around do_xdp_generic() has been introduced in
commit
   bbbe211c ("net: rcu lock and preempt disable missing around generic xdp")

For BPF it is enough to use migrate_disable() and the code was updated
as it can be seen in commit
   3c58482a ("bpf: Provide bpf_prog_run_pin_on_cpu() helper")

This is a leftover which was not converted.

Use migrate_disable() before invoking do_xdp_generic().
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/dev.c

@@ -5277,9 +5277,9 @@ static int __netif_receive_skb_core(struct sk_buff **pskb, bool pfmemalloc,
 	if (static_branch_unlikely(&generic_xdp_needed_key)) {
 		int ret2;
 
-		preempt_disable();
+		migrate_disable();
 		ret2 = do_xdp_generic(rcu_dereference(skb->dev->xdp_prog), skb);
-		preempt_enable();
+		migrate_enable();
 
 		if (ret2 != XDP_PASS) {
 			ret = NET_RX_DROP;