afs: Fix double netfs initialisation in afs_root_iget()

afs: Fix double netfs initialisation in afs_root_iget()

Fix afs_root_iget() to leave initialisation of the netfs_inode part of the
afs_vnode to afs_inode_init_from_status().

Fixes: bc899ee1c898 ("netfs: Add a netfs inode context")
Closes: https://sashiko.dev/#/patchset/20260609081738.770127-1-dhowells%40redhat.com
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://patch.msgid.link/20260622090856.2746629-5-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>