amd64_edac: fix driver instance freeing

Fix use-after-free errors by pushing all memory-freeing calls to the end
of amd64_remove_one_instance().

Reported-by: Darren Jenkins <darrenrjenkins@gmail.com>
LKML-Reference: <1261370306.11354.52.camel@ICE-BOX>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>

drivers/edac/amd64_edac.c

@@ -2929,16 +2929,15 @@ static void __devexit amd64_remove_one_instance(struct pci_dev *pdev)
 
 	amd64_free_mc_sibling_devices(pvt);
 
-	kfree(pvt);
-	mci->pvt_info = NULL;
-
-	mci_lookup[pvt->mc_node_id] = NULL;
-
 	/* unregister from EDAC MCE */
 	amd_report_gart_errors(false);
 	amd_unregister_ecc_decoder(amd64_decode_bus_error);
 
 	/* Free the EDAC CORE resources */
+	mci->pvt_info = NULL;
+	mci_lookup[pvt->mc_node_id] = NULL;
+
+	kfree(pvt);
 	edac_mc_free(mci);
 }