Fix issues with Flogger formatting string not being constant

Resume successful builds on the CI by fixing an Flogger formatting
issue reported by errorprone.

Bug: Issue 16856
Change-Id: Ia0afd707add801aa67a7c2bf390f7f76559c3917

src/main/java/com/googlesource/gerrit/modules/cache/chroniclemap/H2MigrationServlet.java

diff --git a/src/main/java/com/googlesource/gerrit/modules/cache/chroniclemap/H2MigrationServlet.java b/src/main/java/com/googlesource/gerrit/modules/cache/chroniclemap/H2MigrationServlet.java
index 287fe72..c93e44e 100644
--- a/src/main/java/com/googlesource/gerrit/modules/cache/chroniclemap/H2MigrationServlet.java
+++ b/src/main/java/com/googlesource/gerrit/modules/cache/chroniclemap/H2MigrationServlet.java
@@ -171,8 +171,8 @@
     }
 
     logger.atInfo().log("Migrating H2 caches to Chronicle-Map...");
-    logger.atInfo().log("* Size multiplier: " + sizeMultiplier);
-    logger.atInfo().log("* Max Bloat Factor: " + maxBloatFactor);
+    logger.atInfo().log("* Size multiplier: %d", sizeMultiplier);
+    logger.atInfo().log("* Max Bloat Factor: %d", maxBloatFactor);
 
     Config outputChronicleMapConfig = new Config();
 
@@ -332,7 +332,7 @@
 
     } catch (Exception e) {
       String message = String.format("FATAL: error migrating %s H2 cache", in.name());
-      logger.atSevere().withCause(e).log(message);
+      logger.atSevere().withCause(e).log("%s", message);
       throw RestApiException.wrap(message, e);
     }
   }