mbox_test_request_channel() function returns NULL or
error value embedded in the pointer (PTR_ERR).
Evaluate the return value using IS_ERR_OR_NULL.

Signed-off-by: Minjie Du <duminjie@vivo.com>
---
 drivers/mailbox/mailbox-test.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mailbox/mailbox-test.c b/drivers/mailbox/mailbox-test.c
index fc6a12a51..560c0fd98 100644
--- a/drivers/mailbox/mailbox-test.c
+++ b/drivers/mailbox/mailbox-test.c
@@ -390,7 +390,7 @@ static int mbox_test_probe(struct platform_device *pdev)
 	tdev->tx_channel = mbox_test_request_channel(pdev, "tx");
 	tdev->rx_channel = mbox_test_request_channel(pdev, "rx");
 
-	if (!tdev->tx_channel && !tdev->rx_channel)
+	if (IS_ERR_OR_NULL(tdev->tx_channel) && IS_ERR_OR_NULL(tdev->rx_channel))
 		return -EPROBE_DEFER;
 
 	/* If Rx is not specified but has Rx MMIO, then Rx = Tx */
-- 
2.39.0