x86, mce, AMD: Fix leaving freed data in a list

b may be added to a list, but is not removed before being freed
in the case of an error.  This is done in the corresponding
deallocation function, so the code here has been changed to
follow that.

The sematic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression E,E1,E2;
identifier l;
@@

*list_add(&E->l,E1);
... when != E1
    when != list_del(&E->l)
    when != list_del_init(&E->l)
    when != E = E2
*kfree(E);// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: Borislav Petkov <borislav.petkov@amd.com>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: <stable@kernel.org>
Link: http://lkml.kernel.org/r/1305294731-12127-1-git-send-email-julia@diku.dk
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/cpu/mcheck/mce_amd.c

@@ -509,6 +509,7 @@ static __cpuinit int allocate_threshold_blocks(unsigned int cpu,
 out_free:
 	if (b) {
 		kobject_put(&b->kobj);
+		list_del(&b->miscj);
 		kfree(b);
 	}
 	return err;