VFS: change lookup_one_common and lookup_noperm_common to take a qstr

These function already take a qstr of course, but they also currently
take a name/len was well and fill in the qstr.
Now they take a qstr that is already filled in, which is what all the
callers have.

Signed-off-by: NeilBrown <neilb@suse.de>
Link: https://lore.kernel.org/r/20250319031545.2999807-7-neil@brown.name


Signed-off-by: Christian Brauner <brauner@kernel.org>