Busybox find does not support -printf

[r2d4]

ref google/cadvisor#1556

From minikube logs:

E1215 05:47:45.344334    3151 fsHandler.go:121] failed to collect filesystem stats - rootDiskErr: <nil>, rootInodeErr: cmd [find /mnt/sda1/var/lib/docker/aufs/diff/6a39f1eca91d049740697123a35f921c180b3251087d80f2f6b0ab0930adca52 -xdev -printf .] failed. stderr: find: unrecognized: -printf

This affects both the b2d ISO and the minikube-iso as they are both using busybox find.