ntfs: free volume-wide resources on fill_super failure

Summary

In the Linux kernel, the following vulnerability has been resolved:

ntfs: free volume-wide resources on fill_super failure

ntfs_fill_super()'s err_out_now path frees only the volume struct via kfree(vol), leaving several vol-owned allocations behind on every mount failure:

- vol->nls_map, loaded by ntfs_init_fs_context() via load_nls_default() (or replaced by an explicit nls= option in ntfs_parse_param()), is never unload_nls()'d.

- vol->volume_label, allocated by load_system_files() through ntfs_ucstonls() once the $Volume name attribute has been parsed, is not released by load_system_files()'s own error labels nor by the fill_super() inline cleanup that only runs on d_make_root() failure. Any later failure inside load_system_files() leaks it.

- vol->lcn_empty_bits_per_page was kvfree()'d in unl_upcase_iput_tmp_ino_err_out_now without clearing the pointer, so it could not be folded into a single common cleanup.

Because the failure paths never call ntfs_volume_free() and never reach the d_make_root() inline cleanup block (it sits above the label and is jumped over by the load_system_files() / kvmalloc failure gotos), these resources accumulate per failed mount attempt with no chance of recovery short of unloading the module. This is a silent leak: the inodes loaded prior to failure remain hashed but generic_shutdown_super() skips evict_inodes() when sb->s_root is unset, so no CHECK_DATA_CORRUPTION warning is emitted either.

Move the per-volume frees down to err_out_now and drop the lcn_empty_bits_per_page kvfree() from the upper label so the cleanup is performed exactly once on every failure path. Using unconditional kvfree() / kfree() / unload_nls() is safe because they all accept NULL and the upper labels that previously freed nls_map (the d_make_root() inline cleanup) already clear the pointer.