Rename 'pipe_info()' to 'get_pipe_info()'

Rename 'pipe_info()' to 'get_pipe_info()'

commit 71993e62a47dabddf10302807d6aa260455503f4 upstream.

.. and change it to take the 'file' pointer instead of an inode, since
that's what all users want anyway.

The renaming is preparatory to exporting it to other users.  The old
'pipe_info()' name was too generic and is already used elsewhere, so
before making the function public we need to use a more specific name.

Cc: Jens Axboe <jaxboe@fusionio.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Jones <davej@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>