PNP / card: add missing put_device() call

This is required so that we give up the last reference to the device.

Signed-off-by: Levente Kurusa <levex@linux.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/pnp/card.c b/drivers/pnp/card.c
index bc00693..874c236 100644
--- a/drivers/pnp/card.c
+++ b/drivers/pnp/card.c
@@ -239,6 +239,7 @@
 	error = device_register(&card->dev);
 	if (error) {
 		dev_err(&card->dev, "could not register (err=%d)\n", error);
+		put_device(&card->dev);
 		return error;
 	}