Revert "mm-video-v4l2: Protect buffer access and increase input buffer size"

This reverts commit be6ea9de.

Reason for revert: regressions at oc-mr1/bullhead

Change-Id: I69398d4fb236289be5f0b79f8db9a3bc30144b90
Bug: 64340487
Bug: 78291359
Bug: 78913375
Merged-In: Ie9caad90482698913db06cdb9aeebfd869fe1a6a