block: fix blktrace debugfs entries leakage

In the Linux kernel, the following vulnerability has been resolved: block: fix blktrace debugfs entries leakage Commit 99d055b4fd4b ("block: remove per-disk debugfs files in blk_unregister_queue") moves blk_trace_shutdown() from blk_release_queue() to blk_unregister_queue(), this is safe if blktrace is created through sysfs, however, there is a regression in corner case. blktrace can still be enabled after del_gendisk() through ioctl if the disk is opened before del_gendisk(), and if blktrace is not shutdown through ioctl before closing the disk, debugfs entries will be leaked. Fix this problem by shutdown blktrace in disk_release(), this is safe because blk_trace_remove() is reentrant.