A small warning popped up on ia64 because inode-map.c was comparing a
u64 object id with the ULL FIRST_FREE_OBJECTID.  My first thought was
that all the OBJECTID constants should contain the u64 cast because
btrfs code deals entirely in u64s.  But then I saw how large that was,
and figured I'd just fix the max() call.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>