threading/queues: add shortcut for packetpool check

Allows code simplifycation in the threading loops.

src/tm-queues.c

@@ -44,6 +44,7 @@ Tmq *TmqCreateQueue(const char *name)
         goto error;
 
     q->id = tmq_id++;
+    q->is_packet_pool = (strcmp(q->name, "packetpool") == 0);
 
     SCLogDebug("created queue \'%s\', %p", name, q);
     return q;

src/tm-queues.h

@@ -26,6 +26,7 @@
 
 typedef struct Tmq_ {
     char *name;
+    bool is_packet_pool;
     uint16_t id;
     uint16_t reader_cnt;
     uint16_t writer_cnt;