tls: Remove dead code in tls_sw_sendmsg

tls_push_record either returns 0 on success or a negative value on failure.
This patch removes code that would only be executed if tls_push_record
were to return a positive value.

Signed-off-by: Doron Roberts-Kedes <doronrk@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>