libsensors: Report I/O errors as such.

git-svn-id: http://lm-sensors.org/svn/lm-sensors/branches/lm-sensors-3.0.0@4899 7894878c-1315-0410-8ee3-d5d059ff63e0

lib/error.c

@@ -42,6 +42,7 @@ static const char *errorlist[] = {
 	/* SENSORS_ERR_BUS_NAME  */ "Can't parse bus name",
 	/* SENSORS_ERR_PARSE     */ "General parse error",
 	/* SENSORS_ERR_ACCESS_W  */ "Can't write",
+	/* SENSORS_ERR_IO        */ "I/O error",
 };
 
 const char *sensors_strerror(int errnum)