Revert "getVolumeUUID: add workaround to fetch FUSE-mapped sdcard UUID"

This reverts commit 451594b5d15b5858a2b7fdac2e86c9ba952d6e76.

See http://review.cyanogenmod.org/#/c/63097/

Change-Id: I701ec237870e8245f6a4ae36291ab2f645f35780