Rename our 'task_spawn' to 'task_spawn_cmd' since NuttX now has its own version of task_spawn that's different.

src/modules/multirotor_pos_control/multirotor_pos_control.c

@@ -94,7 +94,7 @@ usage(const char *reason)
  * Makefile does only apply to this management task.
  * 
  * The actual stack size should be set in the call
- * to task_spawn().
+ * to task_spawn_cmd().
  */
 int multirotor_pos_control_main(int argc, char *argv[])
 {
@@ -110,7 +110,7 @@ int multirotor_pos_control_main(int argc, char *argv[])
 		}
 
 		thread_should_exit = false;
-		deamon_task = task_spawn("multirotor pos control",
+		deamon_task = task_spawn_cmd("multirotor pos control",
 					 SCHED_DEFAULT,
 					 SCHED_PRIORITY_MAX - 60,
 					 4096,