Hotfix: Changed all left-over task_spawn() to task_spawn_cmd()

src/examples/fixedwing_control/main.c

@@ -512,7 +512,7 @@ usage(const char *reason)
  * Makefile does only apply to this management task.
  *
  * The actual stack size should be set in the call
- * to task_create().
+ * to task_spawn_cmd().
  */
 int ex_fixedwing_control_main(int argc, char *argv[])
 {