From: viro@parcelfarce.linux.theplanet.co.uk <viro@parcelfarce.linux.theplanet.co.uk>

presto_journal_close() switched to passing struct presto_file_data * instead
of bogus struct file *.  The only field of struct file we used to look at was
file->private_data and most of the callers allocated on-stack struct file,
assigned file.private_data and passed the sucker to presto_journal_close().
Idiocy removed.

Looks like they started with case where the data they wanted all along was,
indeed, in ->private_data of already available struct file, so they just
passed pointer to struct file.  And when they found that they need to call it
in other places where there was no such struct file, they'd done it the dumb
way instead of fixing the prototype...