Fix mrbc error for space included path

tasks/mruby_build_commands.rake

@@ -259,7 +259,7 @@ module MRuby
       infiles.each do |f|
         _pp "MRBC", f.relative_path, nil, :indent => 2
       end
-      IO.popen("#{filename @command} #{@compile_options % {:funcname => funcname}} #{infiles.join(' ')}", 'r+') do |io|
+      IO.popen("#{filename @command} #{@compile_options % {:funcname => funcname}} #{filename(infiles).join(' ')}", 'r+') do |io|
         out.puts io.read
       end
     end