Fix up fea_loss calculator (for validation)

Not sure how this was working in regular training mode, but it
was failing in DDP.

codes/models/ExtensibleTrainer.py

@@ -240,8 +240,8 @@ class ExtensibleTrainer(BaseModel):
 
     def compute_fea_loss(self, real, fake):
         with torch.no_grad():
-            logits_real = self.netF(real)
-            logits_fake = self.netF(fake)
+            logits_real = self.netF(real.to(self.device))
+            logits_fake = self.netF(fake.to(self.device))
         return nn.L1Loss().to(self.device)(logits_fake, logits_real)
 
     def test(self):

codes/models/SRGAN_model.py

@@ -883,7 +883,7 @@ class SRGANModel(BaseModel):
         with torch.no_grad():
             real = real.unsqueeze(dim=0).to(self.device)
             fake = fake.unsqueeze(dim=0).to(self.device)
-            real_fea = self.netF(real).detach()
+            real_fea = self.netF(real)
             fake_fea = self.netF(fake)
             return self.cri_fea(fake_fea, real_fea).item()