[ARMedslack] UBI support is [partially] broken in Slackware/ARM 13.1 on SheevaPlug

[Stuart Winter]

Hi Cédric

>     CONFIG_MTD_NAND_VERIFY_WRITE enabled in your kernel, you will need

I've changed this for the next build of -current's kernel, but won't fix
it in 13.1 because writing to NAND isn't documented as a supported
installation method.