netlink_init.c: Memory leak

Found by `-fsanitize=address`.

targets/RT/USER/lte-softmodem.c

@@ -803,6 +803,7 @@ int main ( int argc, char **argv )
     }
   }
 
+  pdcp_module_cleanup();
   terminate_opt();
   logClean();
   printf("Bye.\n");

targets/RT/USER/lte-uesoftmodem.c

@@ -834,6 +834,7 @@ int main( int argc, char **argv ) {
   if (PHY_vars_UE_g[0][0]->rfdevice.trx_end_func)
     PHY_vars_UE_g[0][0]->rfdevice.trx_end_func(&PHY_vars_UE_g[0][0]->rfdevice);
 
+  pdcp_module_cleanup();
   terminate_opt();
   logClean();
   printf("Bye.\n");