syncookies: fix inclusion of tcp options in syn-ack

[ Upstream commit 8b5f12d04b2e93842f3dda01f029842047bf3f81 ]

David Miller noticed that commit
33ad798c924b4a1afad3593f2796d465040aadd5 '(tcp: options clean up')
did not move the req->cookie_ts check.
This essentially disabled commit 4dfc2817025965a2fc78a18c50f540736a6b5c24
'[Syncookies]: Add support for TCP options via timestamps.'.

This restores the original logic.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>