Merge branch 'tcp_metrics-four-fixes'

Eric Dumazet says:

====================
tcp_metrics: four fixes

Looking at an inconclusive syzbot report, I was surprised
to see that tcp_metrics cache on my host was full of
useless entries, even though I have
/proc/sys/net/ipv4/tcp_no_metrics_save set to 1.

While looking more closely I found a total of four issues.
====================

Link: https://lore.kernel.org/r/20230922220356.3739090-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>