fadump: Invalidate the fadump registration during machine shutdown.

If dump is active during system reboot, shutdown or halt then invalidate
the fadump registration as it does not get invalidated automatically.
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/kernel/setup-common.c

@@ -110,6 +110,14 @@ EXPORT_SYMBOL(ppc_do_canonicalize_irqs);
 /* also used by kexec */
 void machine_shutdown(void)
 {
+#ifdef CONFIG_FA_DUMP
+	/*
+	 * if fadump is active, cleanup the fadump registration before we
+	 * shutdown.
+	 */
+	fadump_cleanup();
+#endif
+
 	if (ppc_md.machine_shutdown)
 		ppc_md.machine_shutdown();
 }