fixing el7 VS errors
fixing el7 VS errors

VS warnings 4250 and 4503
BPSerializer::m_Mutex as protected is not valid in el7

VS 2015 warning

JasonRuonanWang/ADIOS2,JasonRuonanWang/ADIOS2,ornladios/ADIOS2,ornladios/ADIOS2,ornladios/ADIOS2,ornladios/ADIOS2,JasonRuonanWang/ADIOS2,JasonRuonanWang/ADIOS2,ornladios/ADIOS2,JasonRuonanWang/ADIOS2