Fix various usages of the Flogger API

- Don't use String.format; instead pass the string directly and let
  Flogger do the formatting. This means the formatting is only done
  when thte log level is enabled.

- Pass exception via withCause rather than as an unreferenced vararg.

- When explicitly passing an exception as vararg with the intention of
  not logging a stack trace, call getMessage() instead of just passing
  the exception object.

Change-Id: Icfe0712b5ebd1d05c630363853a311d734674d14

java/com/google/gerrit/httpd/auth/openid/OpenIdServiceImpl.java

@@ -284,7 +284,7 @@ class OpenIdServiceImpl {
         // right now. Instead of blocking all of them log the error and
         // let the authentication complete anyway.
         //
-        logger.atSevere().log("Invalid PAPE response %s: %s", openidIdentifier, err);
+        logger.atSevere().withCause(err).log("Invalid PAPE response from %s", openidIdentifier);
         unsupported = true;
         ext = null;
       }

java/com/google/gerrit/server/config/PluginConfigFactory.java

@@ -230,7 +230,8 @@ public class PluginConfigFactory implements ReloadPluginListener {
       cfg.load();
     } catch (ConfigInvalidException e) {
       // This is an error in user input, don't spam logs with a stack trace.
-      logger.atWarning().log("Failed to load %s: %s", pluginConfigFile.toAbsolutePath(), e);
+      logger.atWarning().log(
+          "Failed to load %s: %s", pluginConfigFile.toAbsolutePath(), e.getMessage());
     } catch (IOException e) {
       logger.atWarning().withCause(e).log("Failed to load %s", pluginConfigFile.toAbsolutePath());
     }

java/com/google/gerrit/server/notedb/CommentJsonMigrator.java

@@ -158,10 +158,8 @@ public class CommentJsonMigrator {
         return true;
       }
     } catch (IOException e) {
-      logger.atInfo().log(
-          String.format(
-              "Error reading change %s in %s; attempting migration anyway", changeId, project),
-          e);
+      logger.atInfo().withCause(e).log(
+          "Error reading change %s in %s; attempting migration anyway", changeId, project);
     }
 
     try {
@@ -201,7 +199,7 @@ public class CommentJsonMigrator {
       bru.addCommand(new ReceiveCommand(oldId, newId, ref.getName()));
       return true;
     } catch (ConfigInvalidException | IOException e) {
-      logger.atInfo().log(String.format("Error migrating change %s in %s", changeId, project), e);
+      logger.atInfo().withCause(e).log("Error migrating change %s in %s", changeId, project);
       return false;
     }
   }

java/com/google/gerrit/server/patch/Text.java

@@ -157,11 +157,11 @@ public class Text extends RawText {
       return Charset.forName(encoding);
 
     } catch (IllegalCharsetNameException err) {
-      logger.atSevere().log("Invalid detected charset name '%s': %s", encoding, err);
+      logger.atSevere().log("Invalid detected charset name '%s': %s", encoding, err.getMessage());
       return ISO_8859_1;
 
     } catch (UnsupportedCharsetException err) {
-      logger.atSevere().log("Detected charset '%s' not supported: %s", encoding, err);
+      logger.atSevere().log("Detected charset '%s' not supported: %s", encoding, err.getMessage());
       return ISO_8859_1;
     }
   }