tls_common.c: Handle inner content type properly on Big Endian

tls_common.c: Handle inner content type properly on Big Endian

When passing the inner content type to msg_callback,
the lowest byte of rec->type needs to be passed instead
of directly passing the rec->type otherwise the value is
incorrect on Big Endian platforms.

Reviewed-by: Paul Dale <ppzgs1@gmail.com>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/28627)