kprobes: unused header files removed

As kernel test robot reported, lib/test_objpool.c (trace:probes/for-next)
has linux/version.h included, but version.h is not used at all. Then more
unused headers are found in test_objpool.c and rethook.c, and all of them
should be removed.

Link: https://lore.kernel.org/all/[email protected]/

Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Signed-off-by: wuqiang.matt <[email protected]>
Acked-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>

Author: mattwuq

kernel/trace/rethook.c

@@ -8,8 +8,6 @@
 #include <linux/preempt.h>
 #include <linux/rethook.h>
 #include <linux/slab.h>
-#include <linux/sort.h>
-#include <linux/smp.h>
 
 /* Return hook list (shadow stack by list) */
 

lib/test_objpool.c

@@ -6,21 +6,15 @@
  * Copyright: [email protected]
  */
 
-#include <linux/version.h>
 #include <linux/errno.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
-#include <linux/sched.h>
-#include <linux/cpumask.h>
 #include <linux/completion.h>
 #include <linux/kthread.h>
-#include <linux/cpu.h>
-#include <linux/cpuset.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
 #include <linux/delay.h>
 #include <linux/hrtimer.h>
-#include <linux/interrupt.h>
 #include <linux/objpool.h>
 
 #define OT_NR_MAX_BULK (16)