Simplify handling of np.random power of two case.
Simplify handling of np.random power of two case.

stonebig/numba,sklam/numba,jriehl/numba,IntelLabs/numba,sklam/numba,seibert/numba,numba/numba,cpcloud/numba,gmarkall/numba,sklam/numba,gmarkall/numba,sklam/numba,gmarkall/numba,stonebig/numba,numba/numba,jriehl/numba,seibert/numba,IntelLabs/numba,IntelLabs/numba,cpcloud/numba,stonebig/numba,gmarkall/numba,cpcloud/numba,IntelLabs/numba,numba/numba,stuartarchibald/numba,stonebig/numba,cpcloud/numba,IntelLabs/numba,stuartarchibald/numba,stuartarchibald/numba,seibert/numba,jriehl/numba,stonebig/numba,jriehl/numba,cpcloud/numba,gmarkall/numba,numba/numba,seibert/numba,stuartarchibald/numba,seibert/numba,sklam/numba,jriehl/numba,numba/numba,stuartarchibald/numba