Adds a sudo before dumpe2fs.
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

ccaapton/vboot_reference,marineam/seismograph,acorn-marvell/vboot_reference,geekboxzone/mmallow_external_vboot_reference,geekboxzone/mmallow_external_vboot_reference,coreboot/vboot,geekboxzone/mmallow_external_vboot_reference,ccaapton/vboot_reference,geekboxzone/mmallow_external_vboot_reference,ccaapton/vboot_reference,geekboxzone/mmallow_external_vboot_reference,acorn-marvell/vboot_reference,acorn-marvell/vboot_reference,ionave/seismograph,acorn-marvell/vboot_reference,ionave/seismograph,marineam/seismograph,marineam/seismograph,ionave/seismograph,coreboot/vboot,coreboot/vboot,marineam/seismograph,ccaapton/vboot_reference,coreboot/vboot,coreboot/vboot