staging: rtl8192u: null check the kzalloc

In rtl8192_init_priv_variable allocation for priv->pFirmware may fail,
so a null check is necessary.priv->pFirmware is accessed later in
rtl8192_adapter_start. I added the check and made appropriate changes
to propagate the errno to the caller.
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>

Link: https://lore.kernel.org/r/20190731141925.29268-1-navid.emamdoost@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8192u/r8192U_core.c

@@ -2096,7 +2096,7 @@ static void rtl8192_SetWirelessMode(struct net_device *dev, u8 wireless_mode)
 }
 
 /* init priv variables here. only non_zero value should be initialized here. */
-static void rtl8192_init_priv_variable(struct net_device *dev)
+static int rtl8192_init_priv_variable(struct net_device *dev)
 {
 	struct r8192_priv *priv = ieee80211_priv(dev);
 	u8 i;
@@ -2223,6 +2223,8 @@ static void rtl8192_init_priv_variable(struct net_device *dev)
 
 	priv->AcmControl = 0;
 	priv->pFirmware = kzalloc(sizeof(rt_firmware), GFP_KERNEL);
+	if (!priv->pFirmware)
+		return -ENOMEM;
 
 	/* rx related queue */
 	skb_queue_head_init(&priv->rx_queue);
@@ -2236,6 +2238,8 @@ static void rtl8192_init_priv_variable(struct net_device *dev)
 	for (i = 0; i < MAX_QUEUE_SIZE; i++)
 		skb_queue_head_init(&priv->ieee80211->skb_drv_aggQ[i]);
 	priv->rf_set_chan = rtl8192_phy_SwChnl;
+
+	return 0;
 }
 
 /* init lock here */
@@ -2605,7 +2609,10 @@ static short rtl8192_init(struct net_device *dev)
 		memcpy(priv->txqueue_to_outpipemap, queuetopipe, 9);
 	}
 #endif
-	rtl8192_init_priv_variable(dev);
+	err = rtl8192_init_priv_variable(dev);
+	if (err)
+		return err;
+
 	rtl8192_init_priv_lock(priv);
 	rtl8192_init_priv_task(dev);
 	rtl8192_get_eeprom_size(dev);