`swclock` does not show read/write errors

[anthumchris]

init.d/swclock does not show errors during boot/shutdown when swclock_file is not readable/writable.

It may help users to know when swclock fails to sync. This error was difficult to track down without having access to openrc shutdown logs, and I simulated in a VM for TTY1 visibility.

Tests

master...anthumchris:__FORK__openrc:swclock

Using those changes above, I'm using swclock with a file on a mounted filesystem defined in /etc/fstab. I added tests that show errors if the files are not readable/writable.

When I login and restart the service, everything works because the filesystems have mounted:

# rc-service swclock restart
 * WARNING: you are stopping a boot service
 * WARNING: you are stopping a boot service
 * Stopping busybox syslog ...                                                [ ok ]
 * [:: swclock ::] Saving - /mnt/sda2/swclock.state is writable? ...          [ ok ]
 * [:: swclock ::] Saving the shutdown time ...                               [ ok ]
 * [:: swclock ::] Setting - /mnt/sda2/swclock.state is readable? ...         [ ok ]
 * [:: swclock ::] Setting the local clock based on last shutdown time ...    [ ok ]

During boot/shutdown, the filesystems are not mounted, and swclock does not show errors for "Setting the local clock..." and "Saving the shutdown time"

Boot

Shutdown