use sysmon_envsys sleep waiting at "rndsrc" when "drvctl -d".
Don't call rnd_detach_source() in sme_remove_event() which is called
from sme_event_unregister_all(). Instead, call rnd_detach_source() in
sysmon_envsys_sensor_detach() and call sysmon_envsys_sensor_detach()
before sme_event_unregister_sensor(). Each sensor(envsys_data) has each
rnd_src, but some sme_events point to the same rnd_src in a sensor.
Calling rnd_detach_souce() twice with the same rnd_src brokes a reference
count in rnd_src. OK'd by pgoyette@.
01bfdbc214