cifs: Don't use certain unnecessary folio_*() functions
Filesystems should use folio->index and folio->mapping, instead of
folio_index(folio), folio_mapping() and folio_file_mapping() since
they know that it's in the pagecache.
Reported-by: Matthew Wilcox <willy@infradead.org> Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: Steve French <sfrench@samba.org>
cc: Paulo Alcantara <pc@manguebit.com>
cc: Ronnie Sahlberg <lsahlber@redhat.com>
cc: Shyam Prasad N <sprasad@microsoft.com>
cc: Tom Talpey <tom@talpey.com>
cc: linux-cifs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org