add RLC AM destructor

lib/include/srslte/upper/rlc_am.h

@@ -71,6 +71,7 @@ class rlc_am
 {
 public:
   rlc_am();
+  ~rlc_am();
   void init(log          *rlc_entity_log_,
             uint32_t              lcid_,
             srsue::pdcp_interface_rlc   *pdcp_,

lib/src/upper/rlc_am.cc

@@ -68,6 +68,20 @@ rlc_am::rlc_am() : tx_sdu_queue(16)
   do_status     = false;
 }
 
+rlc_am::~rlc_am()
+{
+  // reset RLC and dealloc SDUs
+  stop();
+
+  if(rx_sdu) {
+    pool->deallocate(rx_sdu);
+  }
+
+  if(tx_sdu) {
+    pool->deallocate(tx_sdu);
+  }
+}
+
 void rlc_am::init(srslte::log                 *log_,
                   uint32_t                     lcid_,
                   srsue::pdcp_interface_rlc   *pdcp_,