(maint) only check `builtin_command?` for posix#2518

tvpartytonight wants to merge 1 commit intopuppetlabs:mainpuppetlabs/facter:mainfrom

tvpartytonight:maint_call_builtin_command_posix_onlytvpartytonight/facter:maint_call_builtin_command_posix_onlyCopy head branch name to clipboard