Description: Fix intermittent test_dot failure

test_dot sometimes fails with a slightly out-of-tolerance result,
and comparing to the double precision result suggests most of the
rounding error is in the CPU sdot used as a reference,
not libgpuarray's result.

Author: Rebecca N. Palmer <rebecca_palmer@zoho.com>
Forwarded: https://github.com/Theano/libgpuarray/pull/584

--- a/pygpu/tests/test_blas.py
+++ b/pygpu/tests/test_blas.py
@@ -37,10 +37,7 @@ def dot(N, dtype, offseted_i, sliced, ov
     else:
         gZ = None
 
-    if dtype == 'float32':
-        cr = fblas.sdot(cX, cY)
-    else:
-        cr = fblas.ddot(cX, cY)
+    cr = fblas.ddot(cX, cY)
     gr = gblas.dot(gX, gY, gZ, overwrite_z=overwrite)
     numpy.testing.assert_allclose(cr, numpy.asarray(gr), rtol=1e-6)