Add watches for throttling reported by the OCC

Add Error objects to watch the sysfs entries provided by the OCC hwmon
driver that report various types of throttling. Also needed to add a
boolean input to the Error callback interface.

Resolves openbmc/openbmc#1821

Change-Id: I4425770a92ace0f73024b3dc4c577ce46957a62a
Signed-off-by: Eddie James <eajames@us.ibm.com>
diff --git a/occ_errors.cpp b/occ_errors.cpp
index fc24310..ee41db9 100644
--- a/occ_errors.cpp
+++ b/occ_errors.cpp
@@ -117,18 +117,10 @@
     // A non-zero data indicates an error condition
     // Let the caller take appropriate action on this
     auto data = readFile(len);
-    log<level::INFO>("Error file updated",
-                     entry("ERROR=%s", data.c_str()));
-    if (data.empty() ||
-            data.front() == NO_ERROR)
-    {
-        return;
-    }
-
-    // This must be an error
+    bool error = !(data.empty() || data.front() == NO_ERROR);
     if (callBack)
     {
-        callBack();
+        callBack(error);
     }
     return;
 }