remove not used code that used not existing variable.

theano/sandbox/cuda/opt.py

@@ -666,9 +666,6 @@ def local_gpu_careduce(node):
                                 "WARNING: local_gpu_careduce got type wrong"
                             return None
 
-                        raise Exception(
-                            "GpuCAReduce does not yet implement this pattern:",
-                            pattern)
     return False