io.c: simplified pipe_del_fptr
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62120 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
io.c: simplified pipe_del_fptr
the loop for the rest.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62120 b2dd03c8-39d4-4d8f-98ff-823fe69b080e