Fix scan handling of error when on CVM.

theano/scan_module/scan_op.py

@@ -989,7 +989,7 @@ class Scan(PureOp):
                     # done by raise_with_op is not implemented in C.
                     if hasattr(self.fn, 'thunks'):
                         # For the CVM
-                        gof.vm.raise_with_op(self.fn.nodes[self.fn.position_of_error],
+                        gof.link.raise_with_op(self.fn.nodes[self.fn.position_of_error],
                                                self.fn.thunks[self.fn.position_of_error])
                     else:
                         # For the c linker

theano/scan_module/scan_perform.pyx

@@ -337,7 +337,7 @@ def perform(
                 # this is a new vm-provided function
                 # the C VM needs this because the exception manipulation
                 # done by raise_with_op is not implemented in C.
-                gof.vm.raise_with_op(fn.nodes[fn.position_of_error])
+                gof.link.raise_with_op(fn.nodes[fn.position_of_error])
             else:
                 # old-style linkers raise their own exceptions
                 raise