C2VdaBqBlockPool: remove unnecessary namespace prefix for status_t

This CL removes the unnecessary "android" namespace prefix for
status_t constant. Also it replaces "NO_ERROR" to "OK", which is the
preferred constant.

Bug: 160110407
Test: m -j32

Change-Id: Ia93e82d6425812b169b85ee96b5d3db0d1c23214