fru-dump includes local headers, where recent commit changed fru_alloc
to correctly receive size_t.  fru-dump has it's own local implementation,
which was still receiving an "int" argument. Thus build failed in 64-bit
(and I wonder why my compiler doesn't even warn in 32 bits.

But reported and fix suggested by Michel Vincent, in private email.
Signed-off-by: Alessandro Rubini <rubini@gnudd.com>