Adds a sudo before dumpe2fs.

Looks like dumpe2fs is not in the path otherwise. Also added a check to look for it as a pre-requisite.

BUG=none
TEST=none

Change-Id: I329c894597bc1638043a67359465e55b2ce6d0f7

Review URL: http://codereview.chromium.org/3355013
1 file changed