kernel/sysctl.c: Remove trailing white space

This patch removes the trailing white space in kernel/sysysctl.c
Signed-off-by: Fanjun Kong <bh1scw@gmail.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
[mcgrof: fix commit message subject]
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>