redo: radix tree test suite: fix compilation

[ This resurrects commit 53855d10f456, which was reverted in
2b41226b39b6. It depended on commit d544abd5ff7d ("lib/radix-tree:
Convert to hotplug state machine") so now it is correct to apply ]

Patch "lib/radix-tree: Convert to hotplug state machine" breaks the test
suite as it adds a call to cpuhp_setup_state_nocalls() which is not
currently emulated in the test suite. Add it, and delete the emulation
of the old CPU hotplug mechanism.

Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Matthew Wilcox <[e-mail]>
Tested-by: Kirill A. Shutemov <[e-mail]>
Cc: Konstantin Khlebnikov <[e-mail]>
Cc: Ross Zwisler <[e-mail]>
Cc: Matthew Wilcox <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

lib/radix-tree.c

···
 #include <linux/percpu.h>
 #include <linux/slab.h>
 #include <linux/kmemleak.h>
-#include <linux/notifier.h>
 #include <linux/cpu.h>
 #include <linux/string.h>
 #include <linux/bitops.h>

tools/testing/radix-tree/linux/cpu.h

···
-
-#define hotcpu_notifier(a, b)
-
-#define CPU_ONLINE		0x0002 /* CPU (unsigned)v is up */
-#define CPU_UP_PREPARE		0x0003 /* CPU (unsigned)v coming up */
-#define CPU_UP_CANCELED		0x0004 /* CPU (unsigned)v NOT coming up */
-#define CPU_DOWN_PREPARE	0x0005 /* CPU (unsigned)v going down */
-#define CPU_DOWN_FAILED		0x0006 /* CPU (unsigned)v NOT going down */
-#define CPU_DEAD		0x0007 /* CPU (unsigned)v dead */
-#define CPU_POST_DEAD		0x0009 /* CPU (unsigned)v dead, cpu_hotplug
-					* lock is dropped */
-#define CPU_BROKEN		0x000C /* CPU (unsigned)v did not die properly,
-					* perhaps due to preemption. */
-#define CPU_TASKS_FROZEN	0x0010
-
-#define CPU_ONLINE_FROZEN	(CPU_ONLINE | CPU_TASKS_FROZEN)
-#define CPU_UP_PREPARE_FROZEN	(CPU_UP_PREPARE | CPU_TASKS_FROZEN)
-#define CPU_UP_CANCELED_FROZEN  (CPU_UP_CANCELED | CPU_TASKS_FROZEN)
-#define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
-#define CPU_DOWN_FAILED_FROZEN  (CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
-#define CPU_DEAD_FROZEN		(CPU_DEAD | CPU_TASKS_FROZEN)
+#define cpuhp_setup_state_nocalls(a, b, c, d)	(0)

tools/testing/radix-tree/linux/notifier.h

···
-#ifndef _NOTIFIER_H
-#define _NOTIFIER_H
-
-struct notifier_block;
-
-#define NOTIFY_OK              0x0001          /* Suits me */
-
-#endif