staging: rtl8712: Remove NULL comparison

Remove NULL comparison by using '!' operator. Problem found using
checkpatch.pl
CHECK: Comparison to NULL could be written "!padapter->halpriv.hal_bus_init"
Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8712/hal_init.c

@@ -382,7 +382,7 @@ uint rtl8712_hal_deinit(struct _adapter *padapter)
 uint rtl871x_hal_init(struct _adapter *padapter)
 {
 	padapter->hw_init_completed = false;
-	if (padapter->halpriv.hal_bus_init == NULL)
+	if (!padapter->halpriv.hal_bus_init)
 		return _FAIL;
 	if (padapter->halpriv.hal_bus_init(padapter) != _SUCCESS)
 		return _FAIL;