powerpc/fadump: define an empty fadump_cleanup()

To avoid #ifdefs, define an static inline fadump_cleanup() function
when CONFIG_FADUMP is not selected

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/kernel/setup-common.c

@@ -134,13 +134,11 @@ int crashing_cpu = -1;
 /* 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();