*.torchscript inference `self.jit` fix (#6007)

models/common.py

@@ -379,7 +379,7 @@ class DetectMultiBackend(nn.Module):
     def forward(self, im, augment=False, visualize=False, val=False):
         # YOLOv5 MultiBackend inference
         b, ch, h, w = im.shape  # batch, channel, height, width
-        if self.pt:  # PyTorch
+        if self.pt or self.jit:  # PyTorch
             y = self.model(im) if self.jit else self.model(im, augment=augment, visualize=visualize)
             return y if val else y[0]
         elif self.coreml:  # CoreML