tools/systemd/time: fix selection for multiple options

if we give multiple options/ranges for a value, e.g.
2,4,8
we always choose the biggest, instead of the smallest that is next

this happens because in DateTimeValue::find_next(value)
'next' can be set multiple times and we set it when the new
value was *bigger* than the last found 'next' value, when in reality
we have to choose the *smallest* next we can find

reverse the comparison operator to fix this

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>

src/tools/systemd/time.rs

@@ -54,7 +54,7 @@ impl DateTimeValue {
         let mut next: Option<u32> = None;
         let mut set_next = |v: u32| {
             if let Some(n) = next {
-                if v > n { next = Some(v); }
+                if v < n { next = Some(v); }
             } else {
                 next = Some(v);
             }