If g_convert fails, set bytes_written to 0 and close the iconv descriptor

If g_convert fails, set bytes_written to 0 and close the iconv descriptor

2002-01-21  Jeffrey Stedfast  <fejj@ximian.com>

	* glib/gconvert.c (g_convert_with_fallback): If g_convert fails,
	set bytes_written to 0 and close the iconv descriptor that was
	opened a few lines above. On a successful return, calculate
	bytes_written to be outp - dest instead of outp - str.