MINOR: proto_tcp: use chunk_appendf() to ouput socket setup errors

MINOR: proto_tcp: use chunk_appendf() to ouput socket setup errors

Right now only the last warning or error is reported from
tcp_bind_listener(), but it is useful to report all warnings and no only
the last one, so we now emit them delimited by commas. Previously we used
a fixed buffer of 100 bytes, which was too small to store more than one
message, so let's extend it.

Signed-off-by: Bjoern Jacke <bjacke@samba.org>