ch_ktls: packet handling prior to start marker

There could be a case where ACK for tls exchanges prior to start
marker is missed out, and by the time tls is offloaded. This pkt
should not be discarded and handled carefully. It could be
plaintext alone or plaintext + finish as well.

Fixes: 5a4b9fe7 ("cxgb4/chcr: complete record tx handling")
Signed-off-by: Rohit Maheshwari <rohitm@chelsio.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>