fs/ntfs3: Update inode->i_mapping->a_ops on compression state

Update inode->i_mapping->a_ops when the compression state changes to
ensure correct address space operations.
Clear ATTR_FLAG_SPARSED/FILE_ATTRIBUTE_SPARSE_FILE when enabling
compression to prevent flag conflicts.

v2:
Additionally, ensure that all dirty pages are flushed and concurrent access
to the page cache is blocked.

Fixes: 6b39bfae ("fs/ntfs3: Add support for the compression attribute")
Reported-by: Kun Hu &lt;huk23@m.fudan.edu.cn&gt;, Jiaji Qin <jjtan24@m.fudan.edu.cn>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>