Really revert xDOT changes from 1832
Really revert xDOT changes from 1832

neglected to rebase #1892 on merging
xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS