patch 8.1.2211: listener callback "added" argument is not the total

Problem:    Listener callback "added" argument is not the total. (Andy
            Massimino)
Solution:   Compute the total. (closes #5105)
diff --git a/src/change.c b/src/change.c
index caf9db0..da6a72b 100644
--- a/src/change.c
+++ b/src/change.c
@@ -371,9 +371,9 @@
 	if (start > lnum)
 	    start = lnum;
 	lnum = dict_get_number(li->li_tv.vval.v_dict, (char_u *)"end");
-	if (lnum > end)
+	if (end < lnum)
 	    end = lnum;
-	added = dict_get_number(li->li_tv.vval.v_dict, (char_u *)"added");
+	added += dict_get_number(li->li_tv.vval.v_dict, (char_u *)"added");
     }
     argv[1].v_type = VAR_NUMBER;
     argv[1].vval.v_number = start;