Make dev/mima runnable on Mac OS X.

Mac OS X's find is from the BSD variant that doesn't have -printf option.

Author: Reynold Xin <rxin@apache.org>

Closes #1953 from rxin/mima and squashes the following commits:

e284afe [Reynold Xin] Make dev/mima runnable on Mac OS X.

(cherry picked from commit fa5a08e67d1086045ac249c2090c5e4d0a17b828)
Signed-off-by: Reynold Xin <rxin@apache.org>