memory corruptions.
* grub-core/fs/jfs.c (struct grub_jfs_diropen): Interpret bytes as
unsigned.
(grub_jfs_lookup_symlink): Make ino a grub_uint32_t rather than int.
(grub_jfs_blkno): Use 64-bit quantities for block sectors.
(grub_jfs_read_inode): Likewise.
(grub_jfs_opendir): Likewise. Remove now useless casts.
(grub_jfs_getent): Likewise.
Make ino a grub_uint32_t rather than int.
(grub_jfs_mount): Ensure that blksize and log2_blksize are consistent.
(grub_jfs_read_file): Use 64-bit quantities when necessary. Replace
division and module with bit operations.
(grub_jfs_find_file): Make ino a grub_uint32_t.
(grub_jfs_lookup_symlink): Likewise. Use 64-bit quantities
