net/ipv6: Enforce limits for accept_unsolicited_na sysctl

Fix mistake in the original patch where limits were specified but the
handler didn't take care of the limits.
Signed-off-by: NArun Ajith S <aajith@arista.com>
Reviewed-by: NDavid Ahern <dsahern@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv6/addrconf.c

@@ -7043,7 +7043,7 @@ static const struct ctl_table addrconf_sysctl[] = {
 		.data		= &ipv6_devconf.accept_unsolicited_na,
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
-		.proc_handler	= proc_dointvec,
+		.proc_handler	= proc_dointvec_minmax,
 		.extra1		= (void *)SYSCTL_ZERO,
 		.extra2		= (void *)SYSCTL_ONE,
 	},