ACPI: APEI: EINJ: Do not fail einj_init() on faux_device_create() failure

CXL has a symbol dependency on einj_core.ko, so if einj_init() fails then
cxl_core.ko fails to load. Prior to the faux_device_create() conversion,
einj_probe() failures were tracked by the einj_initialized flag without
failing einj_init().

Revert to that behavior and always succeed einj_init() given there is no
way, and no pressing need, to discern faux device-create vs device-probe
failures.

This situation arose because CXL knows proper kernel named objects to
trigger errors against, but acpi-einj knows how to perform the error
injection. The injection mechanism is shared with non-CXL use cases. The
result is CXL now has a module dependency on einj-core.ko, and init/probe
failures are handled at runtime.

Fixes: 6cb9441 ("ACPI: APEI: EINJ: Transition to the faux device interface")
Signed-off-by: Dan Williams <[email protected]>
Reviewed-by: Ben Cheatham <[email protected]>
Acked-by: Greg Kroah-Hartman <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Rafael J. Wysocki <[email protected]>

Author: djbw

drivers/acpi/apei/einj-core.c

@@ -883,19 +883,16 @@ static int __init einj_init(void)
 	}
 
 	einj_dev = faux_device_create("acpi-einj", NULL, &einj_device_ops);
-	if (!einj_dev)
-		return -ENODEV;
 
-	einj_initialized = true;
+	if (einj_dev)
+		einj_initialized = true;
 
 	return 0;
 }
 
 static void __exit einj_exit(void)
 {
-	if (einj_initialized)
-		faux_device_destroy(einj_dev);
-
+	faux_device_destroy(einj_dev);
 }
 
 module_init(einj_init);