net: dst_cache: annotate data-races around dst_cache->reset_ts

dst_cache->reset_ts is read or written locklessly,
add READ_ONCE() and WRITE_ONCE() annotations.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240507132000.614591-1-edumazet@google.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>