fixed bug in model.test_if_cuda

solver.py

@@ -176,7 +176,7 @@ class Solver():
                     X = torch.unsqueeze(X, dim= 1)
                     y = torch.unsqueeze(y, dim= 1)
 
-                    if model.test_if_cuda():
+                    if model.test_if_cuda:
                         X = X.cuda(self.device, non_blocking=True)
                         y = y.cuda(self.device, non_blocking=True)