Fixed assignment to catch block parameter (opensearch-project#15384)

Signed-off-by: Dmitry Kryukov <dk2k@ya.ru>

Author: dk2k

server/src/main/java/org/opensearch/search/SearchService.java

@@ -721,14 +721,15 @@ private SearchPhaseResult executeQueryPhase(ShardSearchRequest request, SearchSh
             }
         } catch (Exception e) {
             // execution exception can happen while loading the cache, strip it
-            if (e instanceof ExecutionException) {
-                e = (e.getCause() == null || e.getCause() instanceof Exception)
-                    ? (Exception) e.getCause()
-                    : new OpenSearchException(e.getCause());
+            Exception exception = e;
+            if (exception instanceof ExecutionException) {
+                exception = (exception.getCause() == null || exception.getCause() instanceof Exception)
+                    ? (Exception) exception.getCause()
+                    : new OpenSearchException(exception.getCause());
             }
-            logger.trace("Query phase failed", e);
-            processFailure(readerContext, e);
-            throw e;
+            logger.trace("Query phase failed", exception);
+            processFailure(readerContext, exception);
+            throw exception;
         } finally {
             taskResourceTrackingService.writeTaskResourceUsage(task, clusterService.localNode().getId());
         }