rt: Remove a bogus FIXME from ~rust_task

Author: brson

src/rt/rust_task.cpp

@@ -227,9 +227,7 @@ rust_task::~rust_task()
     //   (ref_count == 1 && this == sched->root_task));
 
     // Delete all the stacks. There may be more than one if the task failed
-    // FIXME: This is not correct. During unwinding we need to delete
-    // the stacks and record the stack limit, otherwise the stack
-    // stack is corrupted when destructors are running.
+    // and no landing pads stopped to clean up.
     while (stk != NULL) {
         del_stk(this, stk);
     }