staging: rtl8192e: rtl_core: Fix possible null-pointer dereference in _rtl92e_pci_disconnect()

The variable dev is checked in:
  if (dev)

This indicates that it can be NULL. If so, a null-pointer dereference will
occur:
  priv = rtllib_priv(dev);

However, the value of priv is not used in the remaining part of this
function. Thus the else-branch can be removed to fix this posible
null-pointer dereference.
Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Tuo Li <islituo@gmail.com>
Link: https://lore.kernel.org/r/20210811031135.4110-1-islituo@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8192e/rtl8192e/rtl_core.c

@@ -2556,8 +2556,6 @@ static void _rtl92e_pci_disconnect(struct pci_dev *pdev)
 			release_mem_region(pci_resource_start(pdev, 1),
 					pci_resource_len(pdev, 1));
 		}
-	} else {
-		priv = rtllib_priv(dev);
 	}
 
 	pci_disable_device(pdev);