tls: device: push pending open record on splice EOF

tls: device: push pending open record on splice EOF

On kTLS device-offload sockets, sendfile() with count > EOF can reach
->splice_eof() with a fully assembled but still-open TLS record left
pending. tls_device_splice_eof() only flushes partially sent records,
so an abrupt close() can drop the final record and the peer receives
a short file.

Fix tls_device_splice_eof() to also push pending open records.
This matches the software path, where splice EOF already flushes
pending open records.

Fixes: d4c1e80b0d1b ("tls/device: Use splice_eof() to flush")
Link: https://lore.kernel.org/netdev/CAMPsyauZ+jzG9AysO0FWv6ZY0kvCUpjX_U7o=oOjCuOQ87BCgg@mail.gmail.com/
Reported-by: Nils Juenemann <nils.juenemann@gmail.com>
Signed-off-by: Rishikesh Jethwani <rjethwani@purestorage.com>
Tested-by: Nils Juenemann <nils.juenemann@gmail.com>
Link: https://patch.msgid.link/20260709224436.1608993-2-rjethwani@purestorage.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>