ntfs: only count successfully cleared runs when freeing clusters

In the Linux kernel, the following vulnerability has been resolved: ntfs: only count successfully cleared runs when freeing clusters ntfs_cluster_free_from_rl_nolock() adds a run's length to nr_freed whenever the error bookkeeping condition is false, which includes cases where ntfs_bitmap_clear_run() actually failed - e.g. a second run failing with the same errno as an earlier one, or any failure after a non-ENOMEM error was already recorded. Since a failed ntfs_bitmap_clear_run() rolls back its partial modifications, no bits were cleared for that run, yet its length still inflates vol->free_clusters, corrupting statfs output and the allocator's free space gate. Only count runs whose bitmap clear succeeded.