Add asserts inside bind, connect and sendto to check input parameters. Remove excessive set_errno() calls after get_socket(), because errno is set inside of get_socket(). Move last sock_set_errno() inside lwip_close.
Add asserts inside bind, connect and sendto to check input parameters. Remove excessive set_errno() calls after get_socket(), because errno is set inside of get_socket(). Move last sock_set_errno() inside lwip_close.