Remove superfluous check
Remove superfluous check

|tls_process_finished| was checking that |peer_finish_md_len| was
non-negative. However neither |tls1_final_finish_mac| or
|ssl3_final_finish_mac| can ever return a negative value, so the check is
superfluous.

Reviewed-by: Tim Hudson <eb0be8e447f673b41b10eda09d63cd72526b0a42@openssl.org>
Reviewed-by: Richard Levitte <5fb523282dd7956571c80524edc2dccfa0bd8234@openssl.org>

openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl