lldp: replace if with assert_cc

LLDP_TX_HOLD or one of the other variables might be changed in the future
resulting in a silent error here if the if was just removed.

Replacement for #2983.

diff --git a/src/network/networkd-lldp-tx.c b/src/network/networkd-lldp-tx.c
index 5af2a31..c940e63 100644 (file)
--- a/src/network/networkd-lldp-tx.c
+++ b/src/network/networkd-lldp-tx.c
@@ -239,9 +239,8 @@ static int link_send_lldp(Link *link) {
         (void) gethostname_strict(&hostname);
         (void) parse_env_file("/etc/machine-info", NEWLINE, "PRETTY_HOSTNAME", &pretty_hostname, NULL);
 
+        assert_cc(LLDP_TX_INTERVAL_USEC * LLDP_TX_HOLD + 1 <= (UINT16_MAX - 1) * USEC_PER_SEC);
         ttl = DIV_ROUND_UP(LLDP_TX_INTERVAL_USEC * LLDP_TX_HOLD + 1, USEC_PER_SEC);
-        if (ttl > (usec_t) UINT16_MAX)
-                ttl = (usec_t) UINT16_MAX;
 
         caps = (link->network && link->network->ip_forward != ADDRESS_FAMILY_NO) ?
                 SD_LLDP_SYSTEM_CAPABILITIES_ROUTER :