batman-adv: properly store the roaming time

in case of a new global entry added because of roaming, the roam_at field must
be properly initiated with the current time. This value will be later use to
purge this entry out on time out (if nobody claims it). Instead roam_at field
is now set to zero in this situation leading to an immediate purging of the
related entry.
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

net/batman-adv/translation-table.c

@@ -726,6 +726,12 @@ int batadv_tt_global_add(struct batadv_priv *bat_priv,
 
 		common->flags = flags;
 		tt_global_entry->roam_at = 0;
+		/* node must store current time in case of roaming. This is
+		 * needed to purge this entry out on timeout (if nobody claims
+		 * it)
+		 */
+		if (flags & BATADV_TT_CLIENT_ROAM)
+			tt_global_entry->roam_at = jiffies;
 		atomic_set(&common->refcount, 2);
 		common->added_at = jiffies;