test_wait_for_single_fd.rb: remove with_pipe helper

IO.pipe natively accepts a block, nowadays.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63422 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/-ext-/wait_for_single_fd/test_wait_for_single_fd.rb

@@ -4,18 +4,8 @@ require 'test/unit'
 class TestWaitForSingleFD < Test::Unit::TestCase
   require '-test-/wait_for_single_fd'
 
-  def with_pipe
-    r, w = IO.pipe
-    begin
-      yield r, w
-    ensure
-      r.close unless r.closed?
-      w.close unless w.closed?
-    end
-  end
-
   def test_wait_for_valid_fd
-    with_pipe do |r,w|
+    IO.pipe do |r,w|
       rc = IO.wait_for_single_fd(w.fileno, RB_WAITFD_OUT, nil)
       assert_equal RB_WAITFD_OUT, rc
     end
@@ -35,7 +25,7 @@ class TestWaitForSingleFD < Test::Unit::TestCase
       ver = $1.to_r
       skip 'FreeBSD <= 8.2' if ver <= 8.2r
     end
-    with_pipe do |r,w|
+    IO.pipe do |r,w|
       wfd = w.fileno
       w.close
       assert_raise(Errno::EBADF) do
@@ -45,7 +35,7 @@ class TestWaitForSingleFD < Test::Unit::TestCase
   end
 
   def test_wait_for_closed_pipe
-    with_pipe do |r,w|
+    IO.pipe do |r,w|
       w.close
       rc = IO.wait_for_single_fd(r.fileno, RB_WAITFD_IN, nil)
       assert_equal RB_WAITFD_IN, rc