[ML] Remove timeout on waiting for DF analytics result processor to complete (#45724)

We cannot know how long the analysis will take to complete thus we should not have
a timeout. Note that if the process crashes, the result processor will pick the
exception due to the stream closing.

Closes #45723

Author: dimitris-athanasiou

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/dataframe/process/AnalyticsResultProcessor.java

@@ -15,7 +15,6 @@
 import java.util.Iterator;
 import java.util.Objects;
 import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.TimeUnit;
 import java.util.function.Consumer;
 import java.util.function.Supplier;
 
@@ -45,12 +44,10 @@ public String getFailure() {
 
     public void awaitForCompletion() {
         try {
-            if (completionLatch.await(30, TimeUnit.MINUTES) == false) {
-                LOGGER.warn("[{}] Timeout waiting for results processor to complete", dataFrameAnalyticsId);
-            }
+            completionLatch.await();
         } catch (InterruptedException e) {
             Thread.currentThread().interrupt();
-            LOGGER.info("[{}] Interrupted waiting for results processor to complete", dataFrameAnalyticsId);
+            LOGGER.error(new ParameterizedMessage("[{}] Interrupted waiting for results processor to complete", dataFrameAnalyticsId), e);
         }
     }