Remove obsoleted TODO comment [ci skip]

looks like it's updated sufficiently

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67661 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

common.mk

@@ -955,7 +955,6 @@ INSNS2VMOPT = --srcdir="$(srcdir)"
 
 srcs_vpath = {$(VPATH)}
 
-# TODO: dependencies on tool/ruby_vm scripts.
 inc_common_headers = $(srcdir)/tool/ruby_vm/views/_copyright.erb $(srcdir)/tool/ruby_vm/views/_notice.erb
 $(srcs_vpath)opt_sc.inc: $(srcdir)/tool/ruby_vm/views/opt_sc.inc.erb $(inc_common_headers)
 $(srcs_vpath)optinsn.inc: $(srcdir)/tool/ruby_vm/views/optinsn.inc.erb $(inc_common_headers)