tcp: annotate data-races in tcp_get_info_chrono_stats()

tcp: annotate data-races in tcp_get_info_chrono_stats()

tcp_get_timestamping_opt_stats() does not own the socket lock,
this is intentional.

It calls tcp_get_info_chrono_stats() while other threads could
change chrono fields in tcp_chrono_set().

I do not think we need coherent TCP socket state snapshot
in tcp_get_timestamping_opt_stats(), I chose to only
add annotations to keep KCSAN happy.

Fixes: 1c885808e456 ("tcp: SOF_TIMESTAMPING_OPT_STATS option for SO_TIMESTAMPING")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260416200319.3608680-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>