scripts/sortextable.c: fix building on non-Linux systems

scripts/sortextable.c fails to compile on non-Linux systems due to the
missing 'linux/types.h' header.

Unless I'm missing something obvious, including the standard 'inttypes.h'
header instead and using uintX_t types instead of __uX types does the
exact same job and doesn't break compilation on non-Linux systems.

Signed-off-by: Daniel Tang <dt.tangr@gmail.com>