fc-fsio: guard against bogus readdir results from the target If the FFS being operated on contains SE K2x0 extended filenames, readdir will return strings that are bad for printing. We need to guard against this possibility, and also against possible other bogosity that could be sent by other alien firmwares.

This host side library contains common modules for tools like fc-tmsh and
g23sh which operate asynchronously.  This code has been factored out of
fc-tmsh.