Staging: rtl8712: os_intfs: Remove unnecessary cast

Explicit type conversions are not required and so, they should be
removed.
Semantic patch used:
@@
type T;
T e;
identifier x;
@@

* T x = (T)e;
Signed-off-by: Shivani Bhardwaj <shivanib134@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8712/os_intfs.c

@@ -333,7 +333,7 @@ u8 r8712_init_drv_sw(struct _adapter *padapter)
 
 u8 r8712_free_drv_sw(struct _adapter *padapter)
 {
-	struct net_device *pnetdev = (struct net_device *)padapter->pnetdev;
+	struct net_device *pnetdev = padapter->pnetdev;
 
 	r8712_free_cmd_priv(&padapter->cmdpriv);
 	r8712_free_evt_priv(&padapter->evtpriv);