benchmark/driver.rb: fix wrong multiline regexp

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63889 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

benchmark/driver.rb

@@ -50,7 +50,7 @@ class BenchmarkDriver
   def build_yaml(file)
     magic_comment = '# prelude' # bm_so_nsieve_bits hangs without magic comment
     name = File.basename(file).sub(/\Abm_/, '').sub(/\.rb\z/, '')
-    script = File.read(file).sub(/^__END__\n(.+\n)*/m, '').sub(/\A(^#.+\n)+/m) do |comment|
+    script = File.read(file).sub(/^__END__\n(.+\n)*/m, '').sub(/\A(^#[^\n]+\n)+/m) do |comment|
       magic_comment = comment
       ''
     end