Adding Logger to FB_LREALFromEPICS

[slacAdpai]

Currently a gate valve that is using the FB_LREALFromEPICS (on one side) to read pressure is closing every so often and we are trying to debug it. According to the archiver, the differential pressure is not ok and causes the valve to close. According to the archiver, both pressure are ok, but it could be a network issue instead. Having the logger point that out would be very helpful.