removes unnecessary checks (#11431)

* removes unnecessary checks

* removes unnecessary checks
diff --git a/extensions-core/lookups-cached-single/src/main/java/org/apache/druid/server/lookup/PollingLookup.java b/extensions-core/lookups-cached-single/src/main/java/org/apache/druid/server/lookup/PollingLookup.java
index 84c20d5..0cfa076 100644
--- a/extensions-core/lookups-cached-single/src/main/java/org/apache/druid/server/lookup/PollingLookup.java
+++ b/extensions-core/lookups-cached-single/src/main/java/org/apache/druid/server/lookup/PollingLookup.java
@@ -132,7 +132,7 @@
       return NullHandling.emptyToNullIfNeeded((String) cache.get(keyEquivalent));
     }
     finally {
-      if (cacheRefKeeper != null && cache != null) {
+      if (cache != null) {
         cacheRefKeeper.doneWithIt();
       }
     }
@@ -162,7 +162,7 @@
       return cache.getKeys(valueEquivalent);
     }
     finally {
-      if (cacheRefKeeper != null && cache != null) {
+      if (cache != null) {
         cacheRefKeeper.doneWithIt();
       }
     }