Update ingest-node.asciidoc

Fixed docs typo

docs/reference/ingest/ingest-node.asciidoc

@@ -1788,7 +1788,7 @@ Converts a string to its uppercase equivalent.
 
 Expands a field with dots into an object field. This processor allows fields
 with dots in the name to be accessible by other processors in the pipeline.
-Otherwise these <<accessing-data-in-pipelines,fields> can't be accessed by any processor.
+Otherwise these <<accessing-data-in-pipelines,fields>> can't be accessed by any processor.
 
 [[dot-expender-options]]
 .Dot Expand Options