Change a print to debug only

Not all fans have to produce readings

Change-Id: I79a29d443b5cb7e319a90111726263d304bba17f
Signed-off-by: James Feist <james.feist@linux.intel.com>
diff --git a/src/ExitAirTempSensor.cpp b/src/ExitAirTempSensor.cpp
index 9e493f0..4983f52 100644
--- a/src/ExitAirTempSensor.cpp
+++ b/src/ExitAirTempSensor.cpp
@@ -181,7 +181,10 @@
             });
         if (findReading == tachReadings.end())
         {
-            std::cerr << "Can't find " << tachName << "in readings\n";
+            if (DEBUG)
+            {
+                std::cerr << "Can't find " << tachName << "in readings\n";
+            }
             return false; // haven't gotten a reading
         }