Revert "mmap write/read returns non-zero when writing successfully"

This reverts commit 677baa50f299607d1460557478f3d98eb84ab6ad.

Reason for revert: b/174994516, b/175089243

Change-Id: Ib023d5fd18044ab487416458d1f52fd72464df8c
(cherry picked from commit a93ba031ee4f42be7e69d4b9ad595a959f8a0c46)
1 file changed