Squashfs: fix corruption checks in squashfs_lookup()
Squashfs: fix corruption checks in squashfs_lookup()

The dir_count and size fields when read from disk are sanity
checked for correctness.  However, the sanity checks only check the
values are not greater than expected.  As dir_count and size were
incorrectly defined as signed ints, this can lead to corrupted values
appearing as negative which are not trapped.

Signed-off-by: Phillip Lougher <21542e38a0b82113edef7e33c378f247e235fb75@squashfs.org.uk>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs