Probing symbols that are not EXPORT()ed

[Alan David Brunelle]

> Figured it out - this works.
>
> global rqs
>
> probe module("*scsi_mod*").function("scsi_dispatch_cmd")
> {
>        rqs <<< ($cmd->request_bufflen / 512)
> }
>
> probe end
> {
>        print(@hist_log(rqs))
>        exit()
> }