which simply means that there was insufficient space on the device to write the new kernel module.
However, I tried this again using a much larger USB device and generated an entirely different error - the update-initramfs trigger attempts to stat /vmlinuz and this a a link to a file that no longer exists, so again the wireless installation fails.
The important bit here is apparently:
Setting up initramfs-tools (0.92bubuntu71) ...
update-initramfs: deferring update (trigger activated)
lzma: Encoder error: -2147467259
which simply means that there was insufficient space on the device to write the new kernel module.
However, I tried this again using a much larger USB device and generated an entirely different error - the update-initramfs trigger attempts to stat /vmlinuz and this a a link to a file that no longer exists, so again the wireless installation fails.