If multiple syns are received in one dispatch for the same time-wait
connection, the first removes the connection while subsequent packets
either lookup a nonexistent or an unrelated connection.
Avoid the former with a check.
Type: fix
Change-Id: Ia5f1b3bbd568566eaf36121206aa12363a15b418
Signed-off-by: Florin Coras <fcoras@cisco.com>