PNP: pnpbios: Use PTR_ERR_OR_ZERO()

Fix ptr_ret.cocci warnings:
drivers/pnp/pnpbios/core.c:584:1-3: WARNING: PTR_ERR_OR_ZERO can be used

Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR

Generated by: scripts/coccinelle/api/ptr_ret.cocci
Signed-off-by: Vasyl Gomonovych <gomonovych@gmail.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/pnp/pnpbios/core.c

@@ -581,10 +581,7 @@ static int __init pnpbios_thread_init(void)
 
 	init_completion(&unload_sem);
 	task = kthread_run(pnp_dock_thread, NULL, "kpnpbiosd");
-	if (IS_ERR(task))
-		return PTR_ERR(task);
-
-	return 0;
+	return PTR_ERR_OR_ZERO(task);
 }
 
 /* Start the kernel thread later: */