HDFS-10878. TestDFSClientRetries#testIdempotentAllocateBlockAndClose throws ConcurrentModificationException. Contributed by Rushabh S Shah.

(cherry picked from commit 382307cbdd94107350fe6fad1acf87d63c9be9d6)

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSClientRetries.java

@@ -103,7 +103,6 @@ import org.mockito.internal.stubbing.answers.ThrowsException;
 import org.mockito.invocation.InvocationOnMock;
 import org.mockito.stubbing.Answer;
 
-import com.google.common.base.Joiner;
 
 /**
  * These tests make sure that DFSClient retries fetching data from DFS
@@ -485,8 +484,7 @@ public class TestDFSClientRetries {
           // complete() may return false a few times before it returns
           // true. We want to wait until it returns true, and then
           // make it retry one more time after that.
-          LOG.info("Called complete(: " +
-              Joiner.on(",").join(invocation.getArguments()) + ")");
+          LOG.info("Called complete:");
           if (!(Boolean)invocation.callRealMethod()) {
             LOG.info("Complete call returned false, not faking a retry RPC");
             return false;