Traditionally time_t is a "long int" which matches "%ld". On 32-bit
systems both are 32-bit, and on 64-bit systems both are 64-bit.

However there are recent efforts to make time_t 64-bit on 32-bit systems.
For example recent versions of glibc support 64-bit time_t on 32-bit systems
if _TIME_BITS=64.

This breaks the previous fact that time_t always matches "%ld".

Fix this by moving to "%lld" and casting inode->time to (long long int)
to ensure it matches.

Fixes issue #260

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