To remove the hard coded proc inode numbers it is necessary to be able to
create the proc inodes during readdir.  The instantiate methods are the subset
of lookup that is needed to accomplish that.

This first step just splits the lookup methods into 2 functions.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>