printk: Fix incorrect __user type in proc_dointvec_minmax_sysadmin()

The move of proc_dointvec_minmax_sysadmin() from kernel/sysctl.c to
kernel/printk/sysctl.c introduced an incorrect __user attribute to the
buffer argument.  I spotted this change in [1] as well as the kernel
test robot.  Revert this change to please sparse:

  kernel/printk/sysctl.c:20:51: warning: incorrect type in argument 3 (different address spaces)
  kernel/printk/sysctl.c:20:51:    expected void *
  kernel/printk/sysctl.c:20:51:    got void [noderef] __user *buffer

Fixes: faaa357a55 ("printk: move printk sysctl to printk/sysctl.c")
Link: https://lore.kernel.org/r/20220104155024.48023-2-mic@digikod.net [1]
Reported-by: kernel test robot <lkp@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Xiaoming Ni <nixiaoming@huawei.com>
Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
Link: https://lore.kernel.org/r/20220203145029.272640-1-mic@digikod.net
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/printk/sysctl.c

@@ -12,7 +12,7 @@
 static const int ten_thousand = 10000;
 
 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
-				void __user *buffer, size_t *lenp, loff_t *ppos)
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	if (write && !capable(CAP_SYS_ADMIN))
 		return -EPERM;