kernel/sysctl.c: finish off the warning comments

I've been chasing these comments around this file all week. Hopefully we're
straight now.

Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

kernel/sysctl.c

···
 		.proc_handler	= &proc_dostring,
 		.strategy	= &sysctl_string,
 	},
-
+/*
+ * NOTE: do not add new entries to this table unless you have read
+ * Documentation/sysctl/ctl_unnumbered.txt
+ */
 	{ .ctl_name = 0 }
 };