Fix `checkCodeOwnerConfigFilesIn(...)` must be used errors

This is blocking our import at Google.

Change-Id: Ic705d8dcc497231ceaa89ebe294475431950c03e
Signed-off-by: Edwin Kempin <ekempin@google.com>

javatests/com/google/gerrit/plugins/codeowners/acceptance/api/CheckCodeOwnerConfigFilesIT.java

diff --git a/javatests/com/google/gerrit/plugins/codeowners/acceptance/api/CheckCodeOwnerConfigFilesIT.java b/javatests/com/google/gerrit/plugins/codeowners/acceptance/api/CheckCodeOwnerConfigFilesIT.java
index 749318b..1ffdd43 100644
--- a/javatests/com/google/gerrit/plugins/codeowners/acceptance/api/CheckCodeOwnerConfigFilesIT.java
+++ b/javatests/com/google/gerrit/plugins/codeowners/acceptance/api/CheckCodeOwnerConfigFilesIT.java
@@ -91,13 +91,17 @@
         .update();
 
     requestScopeOperations.setApiUser(user.id());
-    checkCodeOwnerConfigFilesIn(project); // shouldn't throw an AuthException
+
+    @SuppressWarnings("unused")
+    var unused = checkCodeOwnerConfigFilesIn(project); // shouldn't throw an AuthException
   }
 
   @Test
   public void adminCanCheckCodeOwnerConfigFiles() throws Exception {
     requestScopeOperations.setApiUser(admin.id());
-    checkCodeOwnerConfigFilesIn(project); // shouldn't throw an AuthException
+
+    @SuppressWarnings("unused")
+    var unused = checkCodeOwnerConfigFilesIn(project); // shouldn't throw an AuthException
   }
 
   @Test
@@ -111,7 +115,9 @@
         .update();
 
     requestScopeOperations.setApiUser(user.id());
-    checkCodeOwnerConfigFilesIn(project); // shouldn't throw an AuthException
+
+    @SuppressWarnings("unused")
+    var unused = checkCodeOwnerConfigFilesIn(project); // shouldn't throw an AuthException
   }
 
   @Test