media: flexcop-usb: remove needless check before usb_free_coherent()

usb_free_coherent() is safe with NULL addr and this check is
not required.
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/usb/b2c2/flexcop-usb.c

@@ -419,10 +419,9 @@ static void flexcop_usb_transfer_exit(struct flexcop_usb *fc_usb)
 			usb_free_urb(fc_usb->iso_urb[i]);
 		}
 
-	if (fc_usb->iso_buffer != NULL)
-		usb_free_coherent(fc_usb->udev,
-			fc_usb->buffer_size, fc_usb->iso_buffer,
-			fc_usb->dma_addr);
+	usb_free_coherent(fc_usb->udev, fc_usb->buffer_size,
+			  fc_usb->iso_buffer, fc_usb->dma_addr);
+
 }
 
 static int flexcop_usb_transfer_init(struct flexcop_usb *fc_usb)