Please check the filesystem type on the Ipod. From checking the log resolving the device node from the mount point failed, which happens if the Ipod uses a filesystem different to FAT.
Apart from that, you are running Rockbox Utility as normal user. Installing the bootloader on Ipods requires direct access to the device node. Users usually don't have this, which means that you need to run Rockbox Utility as root (or using sudo). This is only needed for bootloader installation.