[PATCH 9/9] do not check IO#closed? before calling IO#close

[Eric Wong]

IO#close is idempotent since Ruby 2.3, so reduce our instruction
footprint to save some memory.
---
 bin/dtas-readahead      | 2 +-
 lib/dtas/buffer.rb      | 4 ++--
 test/test_buffer.rb     | 2 +-
 test/test_unixserver.rb | 2 +-
 4 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/bin/dtas-readahead b/bin/dtas-readahead
index 75bfbe8..6da5f88 100755
--- a/bin/dtas-readahead
+++ b/bin/dtas-readahead
@@ -205,7 +205,7 @@ def do_open(path)
     timeout = 0 if timeout < 0
   else
     work.each_value(&:close).clear
-    fp.close if fp && !fp.closed?
+    fp.close if fp
     fp = timeout = nil
   end
   r = w.to_io.wait_readable(timeout)
diff --git a/lib/dtas/buffer.rb b/lib/dtas/buffer.rb
index 54487c5..0688af9 100644
--- a/lib/dtas/buffer.rb
+++ b/lib/dtas/buffer.rb
@@ -1,4 +1,4 @@
-# Copyright (C) 2013-2020 all contributors <dtas-all@nongnu.org>
+# Copyright (C) all contributors <dtas-all@nongnu.org>
 # License: GPL-3.0+ <https://www.gnu.org/licenses/gpl-3.0.txt>
 # frozen_string_literal: true
 require 'io/wait'
@@ -45,7 +45,7 @@ def to_hsh
 
   def __dst_error(dst, e)
     warn "dropping #{dst.inspect} due to error: #{e.message} (#{e.class})"
-    dst.close unless dst.closed?
+    dst.close
   end
 
   # This will modify targets
diff --git a/test/test_buffer.rb b/test/test_buffer.rb
index b89a090..a47e2d4 100644
--- a/test/test_buffer.rb
+++ b/test/test_buffer.rb
@@ -11,7 +11,7 @@ class TestBuffer < Testcase
   @@max_size = nil if @@max_size == 0
 
   def teardown
-    @to_close.each { |io| io.close unless io.closed? }
+    @to_close.each(&:close)
   end
 
   def setup
diff --git a/test/test_unixserver.rb b/test/test_unixserver.rb
index b061af0..7e99b9e 100644
--- a/test/test_unixserver.rb
+++ b/test/test_unixserver.rb
@@ -21,7 +21,7 @@ def test_close
   end
 
   def teardown
-    @clients.each { |io| io.close unless io.closed? }
+    @clients.each(&:close)
     if File.exist?(@tmp.path)
       @tmp.close!
     else