fix the regression from "direct-io: Fix negative return from dio read beyond eof"

fix the regression from "direct-io: Fix negative return from dio read beyond eof"

commit 2d4594acbf6d8f75a27f3578476b6a27d8b13ebb upstream.

Sure, it's better to bail out of past-the-eof read and return 0 than return
a bogus negative value on such.  Only we'd better make sure we are bailing out
with 0 and not -ENOMEM...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>