Increase default BUFFER_SIZE to accomodate SGEMM parameters
Increase default BUFFER_SIZE to accomodate SGEMM parameters

in response to compile-time warning from #2551
xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS