Rewrite hfs_get_ushort() and hfs_get_uint() as inline functions so that
their arguments are checked. Use __be16_to_cpu and __be32_to_cpu to
byte-swap the result as needed.
git-svn-id: svn://coreboot.org/openbios/trunk/openbios-devel@549 f158a5a8-5612-0410-a976-696ce0be7e32