Enable readability check

readability-avoid-nested-conditional-operator

With one exception, we already pass this check.  Update the log services
code to make it pass, and update it to use the generated enums.

Tested: Code inspection only.

Change-Id: Ic80a7382beb0f541de4916d7b51e42ed5d5dc542
Signed-off-by: Ed Tanous <ed@tanous.net>
diff --git a/redfish-core/lib/log_services.hpp b/redfish-core/lib/log_services.hpp
index 24f0251..4ea01e3 100644
--- a/redfish-core/lib/log_services.hpp
+++ b/redfish-core/lib/log_services.hpp
@@ -2594,9 +2594,17 @@
     bmcJournalLogEntryJson["Id"] = bmcJournalLogEntryID;
     bmcJournalLogEntryJson["Message"] = std::move(message);
     bmcJournalLogEntryJson["EntryType"] = "Oem";
-    bmcJournalLogEntryJson["Severity"] = severity <= 2   ? "Critical"
-                                         : severity <= 4 ? "Warning"
-                                                         : "OK";
+    log_entry::EventSeverity severityEnum = log_entry::EventSeverity::OK;
+    if (severity <= 2)
+    {
+        severityEnum = log_entry::EventSeverity::Critical;
+    }
+    else if (severity <= 4)
+    {
+        severityEnum = log_entry::EventSeverity::Warning;
+    }
+
+    bmcJournalLogEntryJson["Severity"] = severityEnum;
     bmcJournalLogEntryJson["OemRecordFormat"] = "BMC Journal Entry";
     bmcJournalLogEntryJson["Created"] = std::move(entryTimeStr);
     return 0;