block: provide compat ioctl for BLKZEROOUT

commit 3b3a1814 upstream.

This patch provides the compat BLKZEROOUT ioctl. The argument is a pointer
to two uint64_t values, so there is no need to translate it.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

block/compat_ioctl.c

@@ -689,6 +689,7 @@ long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 	case BLKROSET:
 	case BLKDISCARD:
 	case BLKSECDISCARD:
+	case BLKZEROOUT:
 	/*
 	 * the ones below are implemented in blkdev_locked_ioctl,
 	 * but we call blkdev_ioctl, which gets the lock for us