Set errno to EWOULDBLOCK when there is no full message
Set errno to EWOULDBLOCK when there is no full message

In nopoll_conn_read, if nopoll_conn_get_msg returns NULL, the connection
is still ok and a non-blocking call has been requested, return
EWOULDBLOCK

ASPLes/nopoll,schmidtw/nopoll,schmidtw/nopoll,ASPLes/nopoll,ASPLes/nopoll,ASPLes/nopoll,schmidtw/nopoll,ASPLes/nopoll,schmidtw/nopoll,ASPLes/nopoll,schmidtw/nopoll,schmidtw/nopoll