tpm xen: Remove bogus tpm_chip_unregister

tpm_chip_unregister can only be called after tpm_chip_register.
devm manages the allocation so no unwind is needed here.

Cc: [e-mail]
Fixes: afb5abc262e96 ("tpm: two-phase chip management functions")
Reviewed-by: Jarkko Sakkinen <[e-mail]>
Signed-off-by: Jarkko Sakkinen <[e-mail]>

drivers/char/tpm/xen-tpmfront.c

···
 	rv = setup_ring(dev, priv);
 	if (rv) {
 		chip = dev_get_drvdata(&dev->dev);
-		tpm_chip_unregister(chip);
 		ring_free(priv);
 		return rv;
 	}