networkd: Fix comment

Comment about not being a router is in the wrong place. Router lifetime
is assigned with config_parse_sec().

src/network/networkd-address.c

@@ -1166,8 +1166,7 @@ int config_parse_prefix_lifetime(const char *unit,
                 return 0;
         }
 
-        /* a value of 0xffffffff represents infinity, 0x0 means this host is
-           not a router */
+        /* a value of 0xffffffff represents infinity */
         if (streq(lvalue, "PreferredLifetimeSec"))
                 r = sd_radv_prefix_set_preferred_lifetime(p->radv_prefix,
                                                           (usec + USEC_PER_SEC - 1) / USEC_PER_SEC);

src/network/networkd-radv.c

@@ -55,6 +55,8 @@ int radv_configure(Link *link) {
         if (r < 0)
                 return r;
 
+        /* a value of 0xffffffff represents infinity, 0x0 means this host is
+           not a router */
         r = sd_radv_set_router_lifetime(link->radv,
                                         link->network->router_lifetime_usec);
         if (r < 0)