monitor: Enhance tracing of fan & tach sensor states

Moved the determination of the allowed range of speeds of a tach sensor
from the fan to the tach sensor. Also changed the check for too many
nonfunctional tach sensors to return the count of nonfunctional tach
sensors of a fan so that this could be added to the tracing for when a
fan's functional state is updated.

Signed-off-by: Matthew Barth <msbarth@us.ibm.com>
Change-Id: Id65b8064d203bcc63a70f33d4783706e5cc07d2f
diff --git a/monitor/fan.hpp b/monitor/fan.hpp
index 91ea395..62514f6 100644
--- a/monitor/fan.hpp
+++ b/monitor/fan.hpp
@@ -176,10 +176,9 @@
     bool outOfRange(const TachSensor& sensor);
 
     /**
-     * @brief Returns true if too many sensors are nonfunctional
-     *        as defined by _numSensorFailsForNonFunc
+     * @brief Returns the number sensors that are nonfunctional
      */
-    bool tooManySensorsNonfunctional();
+    size_t countNonFunctionalSensors();
 
     /**
      * @brief Updates the Functional property in the inventory