fs: use the super_block as holder when mounting file systems
The file system type is not a very useful holder as it doesn't allow us
to go back to the actual file system instance. Pass the super_block instead
which is useful when passed back to the file system driver.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Message-Id: <
20230802154131.2221419-7-hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>