btrfs: tracepoints, use correct type for inode number

The size of ino_t depends on 32/64bit architecture type. Btrfs stores
the full 64bit inode anyway so we should use it.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>