mctp: serial: propagage new tty types

mctp: serial: propagage new tty types

In tty, u8 is now used for data, ssize_t for sizes (with possible
negative error codes). Propagate these types (and use unsigned in
next_chunk_len()) to mctp.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Reviewed-by: Jeremy Kerr <jk@codeconstruct.com.au>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jeremy Kerr <jk@codeconstruct.com.au>
Cc: Matt Johnston <matt@codeconstruct.com.au>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org
Link: https://lore.kernel.org/r/20240808103549.429349-7-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>