Fix bug in thrift when input buffer contains more than one frame

Summary: Fix bug in thrift when input buffer contains more than one frame

Test Plan:
Need to write a test in thrift.
For now, my test involves passing GrabTaxi's load test

Reviewers: fadrizul, simon.lim, shahzaib.hassan, whassanwj, zezhou.yu

Differential Revision: http://diff.myteksi.net/D111