sysctl: min/max bounds are optional

sysctl check complains with a WARN() when proc_doulongvec_minmax() or
proc_doulongvec_ms_jiffies_minmax() are used by a vector of longs (with
more than one element), with no min or max value specified.

This is unexpected, given we had a bug on this min/max handling :)

Reported-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: David Miller <davem@davemloft.net>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/sysctl_check.c

@@ -143,15 +143,6 @@ int sysctl_check_table(struct nsproxy *namespaces, struct ctl_table *table)
 				if (!table->maxlen)
 					set_fail(&fail, table, "No maxlen");
 			}
-			if ((table->proc_handler == proc_doulongvec_minmax) ||
-			    (table->proc_handler == proc_doulongvec_ms_jiffies_minmax)) {
-				if (table->maxlen > sizeof (unsigned long)) {
-					if (!table->extra1)
-						set_fail(&fail, table, "No min");
-					if (!table->extra2)
-						set_fail(&fail, table, "No max");
-				}
-			}
 #ifdef CONFIG_PROC_SYSCTL
 			if (table->procname && !table->proc_handler)
 				set_fail(&fail, table, "No proc_handler");