ubifs: Fix RENAME_WHITEOUT support

ubifs: Fix RENAME_WHITEOUT support

BugLink: http://bugs.launchpad.net/bugs/1688485
commit c3d9fda688742c06e89aa1f0f8fd943fc11468cb upstream.

Remove faulty leftover check in do_rename(), apparently introduced in a
merge that combined whiteout support changes with commit f03b8ad8d386
("fs: support RENAME_NOREPLACE for local filesystems")

Fixes: f03b8ad8d386 ("fs: support RENAME_NOREPLACE for local filesystems")
Fixes: 9e0a1fff8db5 ("ubifs: Implement RENAME_WHITEOUT")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>