osmo_sock_init(): include host and port in error messages

For programs like osmo-hnbgw with numerous sockets, the message that some
unspecified connection was refused is not very helpful. Also output the host
and port where an error occured.

Instead of perror, use fprintf(stderr, ..., strerror()) to be able to include a
format string and print host and port as passed to osmo_sock_init().

Change-Id: I8d0343f51310699b78fcb83fd76fd93764acf3dc
1 file changed