[COOK-3302] Fix hdiutil detach failure due to cfprefsd
[COOK-3302] Fix hdiutil detach failure due to cfprefsd

Signed-off-by: Seth Vargo <81550dbf04dfd8537ff7b3c014c6fbf86e0889dc@gmail.com>

opscode-cookbooks/dmg,Sauraus/dmg,JasonGiedymin/dmg,RoboticCheese/dmg,turtlebender/dmg,jeroenj/dmg,thomasmeeus/dmg,wenzowski/dmg,clakeb/dmg,chef-cookbooks/dmg,protec-cookbooks/dmg,irabinovitch/dmg,atlasdigital/dmg,juliandunn/dmg