[C++] Warnings cleanup.
[C++] Warnings cleanup.

PKRoma/simple-binary-encoding,PKRoma/simple-binary-encoding,real-logic/simple-binary-encoding,PKRoma/simple-binary-encoding,real-logic/simple-binary-encoding,PKRoma/simple-binary-encoding,real-logic/simple-binary-encoding,PKRoma/simple-binary-encoding,real-logic/simple-binary-encoding,real-logic/simple-binary-encoding,PKRoma/simple-binary-encoding,real-logic/simple-binary-encoding,real-logic/simple-binary-encoding,PKRoma/simple-binary-encoding