ANDROID: KVM: arm64: Fix psci_mem_protect_dec() on VM reclaim

On VM teardown, the host will reclaim all the pages. We have to account
for PSCI MEM_PROTECT properly there. A typo was preventing a proper
accounting and hence the whole system would be stuck with the
MEM_PROTECT flag on.

Bug: 278749606
Bug: 278011447
Fixes: 39c6e891 ("ANDROID: KVM: arm64: Huge page support for pKVM guest memory reclaim")
Change-Id: Id2987c9d07dbf2f87d015debddf4fd0524025b07
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>