add log_filter dtor

lib/include/srslte/common/log_filter.h

@@ -54,6 +54,7 @@ public:
   log_filter();
   log_filter(std::string layer);
   log_filter(std::string layer, logger *logger_, bool tti=false);
+  ~log_filter();
 
   void init(std::string layer, logger *logger_, bool tti=false);
 

lib/src/common/log_filter.cc

@@ -59,6 +59,10 @@ log_filter::log_filter(std::string layer, logger *logger_, bool tti)
   init(layer, logger_, tti);
 }
 
+log_filter::~log_filter()
+{
+}
+
 void log_filter::init(std::string layer, logger *logger_, bool tti)
 {
   service_name  = layer;