mptcp: add ro_after_init for tcp{,v6}_prot_override

mptcp: add ro_after_init for tcp{,v6}_prot_override

BugLink: https://bugs.launchpad.net/bugs/2016876
commit 822467a48e938e661965d09df5fcac66f7291050 upstream.

Add __ro_after_init labels for the variables tcp_prot_override and
tcpv6_prot_override, just like other variables adjacent to them, to
indicate that they are initialised from the init hooks and no writes
occur afterwards.

Fixes: b19bc2945b40 ("mptcp: implement delegated actions")
Cc: stable@vger.kernel.org
Fixes: 51fa7f8ebf0e ("mptcp: mark ops structures as ro_after_init")
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>