ACPI: bay: use IS_ERR for return of register_platform_device_simple

register_platform_device_simple returns ERR_PTR(foo), so test it with
IS_ERR(foo).

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/bay.c b/drivers/acpi/bay.c
index 73dc10d..9c28081 100644
--- a/drivers/acpi/bay.c
+++ b/drivers/acpi/bay.c
@@ -283,7 +283,7 @@
 
 	/* initialize platform device stuff */
 	pdev = platform_device_register_simple(ACPI_BAY_CLASS, id, NULL, 0);
-	if (pdev == NULL) {
+	if (IS_ERR(pdev)) {
 		printk(KERN_ERR PREFIX "Error registering bay device\n");
 		goto bay_add_err;
 	}