Try to avoid `not delagated` error

```
.../ruby/lib/delegate.rb:405:in `__getobj__': not delegated (ArgumentError)
```
https://rubyci.org/logs/rubyci.s3.amazonaws.com/debian9/ruby-master/log/20190703T063006Z.fail.html.gz

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/tempfile.rb b/lib/tempfile.rb
index f703709113..4678a191a7 100644
--- a/lib/tempfile.rb
+++ b/lib/tempfile.rb
@@ -234,7 +234,7 @@ class Tempfile < DelegateClass(File)
 
   # :stopdoc:
   def inspect
-    if closed?
+    if @tmpfile.closed?
       "#<#{self.class}:#{path} (closed)>"
     else
       "#<#{self.class}:#{path}>"