"tsdb fsck --fix-all" wrongly clears data points when salting enabled
"tsdb fsck --fix-all" wrongly clears data points when salting enabled

Const.SALT_WIDTH() is actually not constant value, it mustn't be
called on class initialization.

Signed-off-by: Chris Larsen <83037b211e1d109d6858769a113e269c3139ffd3@yahoo-inc.com>

alienth/opentsdb,OpenTSDB/opentsdb,MadDogTechnology/opentsdb,OpenTSDB/opentsdb,MadDogTechnology/opentsdb,MadDogTechnology/opentsdb,OpenTSDB/opentsdb,alienth/opentsdb