cosmetic: gscon: don't re-enter ST_CLEARING

I often see "ERROR [ST_CLEARING] Entering ST_CLEARING not permitted!", avoid
the bogus error messages by checking entering ST_CLEARING only if not in it
yet. Still don't allow re-entering, to not restart the timeout.

Change-Id: Ia1f171c08dcbc529f907a20eed43bf5ee3a452b3
1 file changed