log file descriptor in more socket related error messages

log file descriptor in more socket related error messages

This add the fd to the epoll event error message and the x_check_status
message. This helps debugging when thing go wrong with event handling.

Also add logging when ep_del fails to remove a socket from the structure.
In constract to ep_ctl that has this as a FATAL message (M_ERR), we only
log here since the code has been ignoring the status forever there might
be corner cases where a FATAL message could trigger an unintened
regression.

PATCH v2: Fix wrong order of fd,code in printed message.

Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20210403123000.17688-1-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg22008.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>