ANDROID: KVM: arm64: Fix PKVM_NOPAGE assertion

We double check the PKVM_NOPAGE state from the hyp_vmemmap when hitting
an invalid but non-NULL PTE in the host stage-2. But that check is
terminally broken. Oops. Fix it.

Bug: 357781595
Bug: 322736772
Bug: 278749606
Bug: 326193089
Change-Id: I6ea05ac6785b18d41949ef9a0b8be64be3c0dcd8
Signed-off-by: Quentin Perret <qperret@google.com>