kill struct opendata

Just pass struct file *.  Methods are happier that way...
There's no need to return struct file * from finish_open() now,
so let it return int.  Next: saner prototypes for parts in
namei.c

Change-Id: I984f0f992330c959a2f9703d9e7647ef340e2845
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
15 files changed