BackupRef: Add missing cases in switch on RefUpdate.Result

Handle all the other cases as an unexpected result.

Adust the log message to include the value.

Change-Id: I7e2e534c2f26f518f1675a6b9820483b46912e86

src/main/java/com/googlesource/gerrit/plugins/refprotection/BackupRef.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/refprotection/BackupRef.java b/src/main/java/com/googlesource/gerrit/plugins/refprotection/BackupRef.java
index d88df07..f3777f3 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/refprotection/BackupRef.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/refprotection/BackupRef.java
@@ -141,9 +141,14 @@
             case REJECTED:
               log.error("Tag already exists while creating backup tag");
               break;
-
+            case FAST_FORWARD:
+            case IO_FAILURE:
+            case NOT_ATTEMPTED:
+            case NO_CHANGE:
+            case REJECTED_CURRENT_BRANCH:
+            case RENAMED:
             default:
-              log.error("Unknown error while creating backup tag");
+              log.error("Unexpected result while creating backup tag: {}", result);
           }
         } else {
           BranchInput input = new BranchInput();