When an internal function logs an error and its cause, it bloats the log
when the caller logs the cause again.
Signed-off-by: Simon Rozman <simon@rozman.si>
WINTUN_LOGGER_... => LOGGER_... => LOG_...
Those macros are internal, so they don/t need to start with WINTUN_...
Replacing the noun LOGGER_... with the verb LOG_... makes the code more
natural to read now.
Signed-off-by: Simon Rozman <simon@rozman.si>