According to the chackpatch.pl, comparison to NULL could
be written "!chan->rx_skb".
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
         */
        kfree_skb(chan->rx_skb);
        chan->rx_skb = dev_alloc_skb(size);
-       if (chan->rx_skb == NULL) {
+       if (!chan->rx_skb) {
                pr_notice("%s: Memory squeeze, dropping packet\n", chan->name);
                chan->netdev->stats.rx_dropped++;
                return NULL;
                return -ERESTARTSYS;
        
        chan->rxdata = kmalloc(COSA_MTU, GFP_DMA|GFP_KERNEL);
-       if (chan->rxdata == NULL) {
+       if (!chan->rxdata) {
                mutex_unlock(&chan->rlock);
                return -ENOMEM;
        }
        
        /* Allocate the buffer */
        kbuf = kmalloc(count, GFP_KERNEL|GFP_DMA);
-       if (kbuf == NULL) {
+       if (!kbuf) {
                up(&chan->wsem);
                return -ENOMEM;
        }