Remove duplicate exception raise in nvvm.py
Remove duplicate exception raise in nvvm.py

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