namei.c: split unlazy_walk()

In all but one case, the last two arguments are NULL and 0 resp.;
almost everyone just wants to switch nameidata to non-RCU mode.
The only exception is lookup_fast(), where we have a child dentry
we want to legitimize as well.  Split these two cases.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2017-01-09 22:29:15 -05:00
commit 4675ac39b5