Fix random permutation test.
Fix random permutation test.

This fixes the random permutation test. It was sporadically failing
on Python 2.7 as occasionally a permutation was picked that was the
identity permutation and the test was asserting that:

```
input != permutation(input)
```

most of the time as input was large and linear this wasn't a problem
but occasionally for permutations in the first axis on arrays with a
small first dimension the identity permutation would appear and cause
the test to fail.

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