ip: Fix data-races around sysctl_ip_fwd_update_priority.

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2149949


Upstream Status: linux.git

commit 7bf9e18d
Author: Kuniyuki Iwashima <kuniyu@amazon.com>
Date:   Wed Jul 13 13:51:54 2022 -0700

    ip: Fix data-races around sysctl_ip_fwd_update_priority.

    While reading sysctl_ip_fwd_update_priority, it can be changed
    concurrently.  Thus, we need to add READ_ONCE() to its readers.

    Fixes: 432e05d3 ("net: ipv4: Control SKB reprioritization after forwarding")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Guillaume Nault <gnault@redhat.com>