Revert "Use getmntent when accessing /proc/mounts."

This reverts commit a382e2bdb22b5b68d83f32c6c339465b2e8f6e46.

getmntent is not implemented in older Bionic versions.

Change-Id: I277dae9e4fd83f08de8099e856e8d8f45e39239d
1 file changed