sysctl: fix proc_doulongvec_ms_jiffies_minmax()

BugLink: http://bugs.launchpad.net/bugs/1660994

commit ff9f8a7c upstream.

We perform the conversion between kernel jiffies and ms only when
exporting kernel value to user space.

We need to do the opposite operation when value is written by user.

Only matters when HZ != 1000
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

kernel/sysctl.c

@@ -2466,6 +2466,7 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int
 				break;
 			if (neg)
 				continue;
+			val = convmul * val / convdiv;
 			if ((min && val < *min) || (max && val > *max))
 				continue;
 			*i = val;