kernel/sysctl.c: remove unused variable ten_thousand

kernel/sysctl.c: remove unused variable ten_thousand

The const variable ten_thousand is not used, it is redundant and can be
removed.

Cleans up clang warning:

  kernel/sysctl.c:99:18: warning: unused variable 'ten_thousand' [-Wunused-const-variable]
  static const int ten_thousand = 10000;

Link: https://lkml.kernel.org/r/20211221184501.574670-1-colin.i.king@gmail.com
Fixes: c26da54dc8ca ("printk: move printk sysctl to printk/sysctl.c")
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>