If for example you deltask do_build but it has recrdeps set, its confusing
to have that list returned when the task no longer exists (same would apply
to deps too if it was set after the deltask).
(Bitbake rev: b7a81cb91e82ba64b63c9153dc161a2ab4696715)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>