staging: rtl8712: rtl871x_mlme.c: use !x in place of NULL comparison

Challenge suggested by coccinelle.
Avoid NULL comparison, compare using boolean operator.
Signed-off-by: Payal Kshirsagar <payal.s.kshirsagar.98@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8712/rtl871x_mlme.c

@@ -95,7 +95,7 @@ static void _free_network(struct mlme_priv *pmlmepriv,
 	unsigned long irqL;
 	struct  __queue *free_queue = &(pmlmepriv->free_bss_pool);
 
-	if (pnetwork == NULL)
+	if (!pnetwork)
 		return;
 	if (pnetwork->fixed)
 		return;
@@ -115,7 +115,7 @@ static void free_network_nolock(struct mlme_priv *pmlmepriv,
 {
 	struct  __queue *free_queue = &pmlmepriv->free_bss_pool;
 
-	if (pnetwork == NULL)
+	if (!pnetwork)
 		return;
 	if (pnetwork->fixed)
 		return;
@@ -399,7 +399,7 @@ static void update_scanned_network(struct _adapter *adapter,
 			/* Otherwise just pull from the free list */
 			/* update scan_time */
 			pnetwork = alloc_network(pmlmepriv);
-			if (pnetwork == NULL)
+			if (!pnetwork)
 				return;
 			bssid_ex_sz = r8712_get_wlan_bssid_ex_sz(target);
 			target->Length = bssid_ex_sz;
@@ -1120,7 +1120,7 @@ int r8712_select_and_join_from_scan(struct mlme_priv *pmlmepriv)
 		}
 		pnetwork = container_of(pmlmepriv->pscanned,
 					struct wlan_network, list);
-		if (pnetwork == NULL)
+		if (!pnetwork)
 			return _FAIL;
 		pmlmepriv->pscanned = pmlmepriv->pscanned->next;
 		if (pmlmepriv->assoc_by_bssid) {