btrfs.c: cleanup struct btrfs_ioctl_get_dev_stats.nr_items check
btrfs.c: cleanup struct btrfs_ioctl_get_dev_stats.nr_items check

* btrfs.c (btrfs_ioctl): Cleanup check of iterator of
btrfs_ioctl_get_dev_stats.values array.

cuviper/strace,Saruta/strace,cuviper/strace,cuviper/strace,Saruta/strace,cuviper/strace,Saruta/strace,Saruta/strace,Saruta/strace,cuviper/strace