Fix one more method impacted by cherry-picking RUBY-2119 without RUBY-2149

Author: Emily Giurleo

lib/mongo/operation/insert/legacy.rb

@@ -32,7 +32,7 @@ class Legacy
 
         def get_result(server, client, options = {})
           # This is a Mongo::Operation::Insert::Result
-          Result.new(*dispatch_message(server, client), @ids)
+          Result.new(dispatch_message(server, client), @ids)
         end
 
         def selector