Revert "sock: Reset dst when changing sk_mark via setsockopt"

This reverts commit 4c5ce7ca which is
commit 50254256f382c56bde87d970f3d0d02fdb76ec70 upstream.

It breaks a number of runtime Android networking tests, so something is
wrong with the backport, or something else also needed to be backported
at the same time.  So I'm dropping this from the tree as regressions are
not good.

Cc: David Barmann <david.barmann@stackpath.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>