Use non-unit forward_scale in test_gh_109

The test with unit forward scale would have passed both before
and after the fix. With non-unit scale it would have failed
before the fix.

Thanks @vtavana for catching this during review.

Author: oleksandr-pavlyk

mkl_fft/tests/test_fftnd.py

@@ -223,8 +223,8 @@ def test_gh109():
     b_int = np.array([[5, 7, 6, 5], [4, 6, 4, 8], [9, 3, 7, 5]], dtype=np.int64)
     b = np.asarray(b_int, dtype=np.float32)
 
-    r1 = mkl_fft.fftn(b, shape=None, axes=(0,), overwrite_x=False)
-    r2 = mkl_fft.fftn(b_int, shape=None, axes=(0,), overwrite_x=False)
+    r1 = mkl_fft.fftn(b, shape=None, axes=(0,), overwrite_x=False, forward_scale=1/3)
+    r2 = mkl_fft.fftn(b_int, shape=None, axes=(0,), overwrite_x=False, forward_scale=1/3)
 
     rtol, atol = _get_rtol_atol(b)
     assert_allclose(r1, r2, rtol=rtol, atol=atol)