TPM: Add new TPMs to the tail of the list to prevent inadvertent change of dev

commit 398a1e71 upstream.

Add newly registered TPMs to the tail of the list, not the beginning, so that
things that are specifying TPM_ANY_NUM don't find that the device they're
using has inadvertently changed.  Adding a second device would break IMA, for
instance.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/char/tpm/tpm.c

@@ -1341,7 +1341,7 @@ struct tpm_chip *tpm_register_hardware(struct device *dev,
 
 	/* Make chip available */
 	spin_lock(&driver_lock);
-	list_add_rcu(&chip->list, &tpm_chip_list);
+	list_add_tail_rcu(&chip->list, &tpm_chip_list);
 	spin_unlock(&driver_lock);
 
 	return chip;