Fix printf format specifiers for 64 bit integer types

Fix printf format specifiers for 64 bit integer types

In nandflipbits, nandtest and ubiscan, uint64_t integers are printed
to stdout using "%llu" as a format specifier, but on platforms like
x86_64, uint64_t is actually typedef'd as `unsigned long` only.

For compatibillity across platforms, simply use the C99 printfs
macros instead.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>