Fix apparent off-by-one error in calculation of MAX_ALLOCATING_THREADS
Fix apparent off-by-one error in calculation of MAX_ALLOCATING_THREADS

fixes #1641
xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS