ExitAir: Limit error prints

This was spamming the logs on systems with FP disconnected.

Tested: Less logs were there

Change-Id: I0b6ae204c4052317f1200d3adf89d81e518756f2
Signed-off-by: James Feist <james.feist@linux.intel.com>
diff --git a/src/ExitAirTempSensor.cpp b/src/ExitAirTempSensor.cpp
index 0736a55..42ae6db 100644
--- a/src/ExitAirTempSensor.cpp
+++ b/src/ExitAirTempSensor.cpp
@@ -629,7 +629,10 @@
 
 bool ExitAirTempSensor::calculate(double& val)
 {
+    constexpr size_t maxErrorPrint = 1;
     static bool firstRead = false;
+    static size_t errorPrint = maxErrorPrint;
+
     double cfm = getTotalCFM();
     if (cfm <= 0)
     {
@@ -640,7 +643,11 @@
     // if there is an error getting inlet temp, return error
     if (std::isnan(inletTemp))
     {
-        std::cerr << "Cannot get inlet temp\n";
+        if (errorPrint > 0)
+        {
+            errorPrint--;
+            std::cerr << "Cannot get inlet temp\n";
+        }
         val = 0;
         return false;
     }
@@ -684,7 +691,11 @@
 
     if (totalPower == 0)
     {
-        std::cerr << "total power 0\n";
+        if (errorPrint > 0)
+        {
+            errorPrint--;
+            std::cerr << "total power 0\n";
+        }
         val = 0;
         return false;
     }
@@ -758,6 +769,7 @@
     val = reading;
     lastReading = reading;
     lastTime = time;
+    errorPrint = maxErrorPrint;
     return true;
 }