[analysis_server] Fix FILE_NOT_ANALYZED error in completion handler

Change-Id: I18af43f82fb72b013d7dda547d5e0ca528f7558e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/224941
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
diff --git a/pkg/analysis_server/lib/src/domain_completion.dart b/pkg/analysis_server/lib/src/domain_completion.dart
index 692b65f..661049b 100644
--- a/pkg/analysis_server/lib/src/domain_completion.dart
+++ b/pkg/analysis_server/lib/src/domain_completion.dart
@@ -518,8 +518,7 @@
 
         var resolvedUnit = await server.getResolvedUnit(file);
         if (resolvedUnit == null) {
-          server
-              .sendResponse(Response.fileNotAnalyzed(request, 'params.offset'));
+          server.sendResponse(Response.fileNotAnalyzed(request, file));
           return;
         }