inet_sk_rebuild_header() does a new route lookup if the dst_entry
    associated with a socket becomes stale. However inet_sk_rebuild_header()
    didn't use struct flowi->flags, causing the route lookup to
    fail for foreign-bound IP_TRANSPARENT sockets, causing an error
    state to be set for the sockets in question.
Signed-off-by: Balazs Scheidler <bazsi@balabit.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>