staging: r8188eu: Fix a smatch warnings in core/rtw_recv.c

Smatch reports the following:
drivers/staging/rtl8188eu/os_dep/recv_linux.c:227 rtw_recv_indicatepkt() warn: variable dereferenced before check 'precv_frame' (see line 139)

The test in this location is removed and added in the free routine.
Signed-off-by: NLarry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8188eu/core/rtw_recv.c

@@ -208,7 +208,8 @@ int rtw_free_recvframe(union recv_frame *precvframe, struct __queue *pfree_recv_
 	struct recv_priv *precvpriv = &padapter->recvpriv;
 
 _func_enter_;
-
+	if (!precvframe)
+		return _FAIL;
 	if (precvframe->u.hdr.pkt) {
 		dev_kfree_skb_any(precvframe->u.hdr.pkt);/* free skb by driver */
 		precvframe->u.hdr.pkt = NULL;

drivers/staging/rtl8188eu/os_dep/recv_linux.c

@@ -224,7 +224,6 @@ _func_exit_;
 _recv_indicatepkt_drop:
 
 	 /* enqueue back to free_recv_queue */
-	if (precv_frame)
 	rtw_free_recvframe(precv_frame, pfree_recv_queue);
 
 _func_exit_;