ubinize corrections

[J. Scott Merritt]

Dear list,

I believe that I have stumbled upon two problems with the latest version
of ubinize.c in mtd-utils - one serious, and one not so serious.

- First, the easy one: At line 457, I believe that we should be printing
args.subpage_size rather than ui.min_io_size.

- More seriously, I believe that the "flags" field in the ubigen_vol_info
structures is not being properly initialized.  Line 494 allocates memory
for these structures with malloc, so they are not cleared to zero.  The
read_section function updates the flag field if the AUTO-RESIZE flag is
specified, but does not otherwise initialize or clear it.

I reckon the latter problem could be repaired either with calloc, or by
modifying read_section to more directly set/clear the flag.

Thanks, Scott.