asidalloc: Fix inadvertently removed line from UniqueASIDActiveTask

A previous commit inadvertently removed the implication line in the
UniqueASIDActiveTask invariant. Add it back.

Fixes: 50c387fdce00 ("asidalloc: Model PTEs and an asynchronous try_to_unmap_one() call")
Reported-by: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
1 file changed