bpf, ktls: Fix data corruption when using bpf_msg_pop_data() in ktls

In the Linux kernel, the following vulnerability has been resolved:

bpf, ktls: Fix data corruption when using bpf_msg_pop_data() in ktls

When sending plaintext data, we initially calculated the corresponding ciphertext length. However, if we later reduced the plaintext data length via socket policy, we failed to recalculate the ciphertext length.

This results in transmitting buffers containing uninitialized data during ciphertext transmission.

This causes uninitialized bytes to be appended after a complete "Application Data" packet, leading to errors on the receiving end when parsing TLS record.