Format a line of log the same way as the default callback.
@param line buffer to receive the formatted line
@param line_size size of the buffer
@param print_prefix used to store whether the prefix must be printed;
must point to a persistent integer initially set to 1
Format a line of log the same way as the default callback. @param line buffer to receive the formatted line @param line_size size of the buffer @param print_prefix used to store whether the prefix must be printed; must point to a persistent integer initially set to 1