KVM: arm64: Use get_page() instead of kvm_get_pfn()

When mapping a THP, we are guaranteed that the page isn't reserved,
and we can safely avoid the kvm_is_reserved_pfn() call.

Replace kvm_get_pfn() with get_page(pfn_to_page()).
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210726153552.1535838-6-maz@kernel.org

arch/arm64/kvm/mmu.c

@@ -840,7 +840,7 @@ transparent_hugepage_adjust(struct kvm *kvm, struct kvm_memory_slot *memslot,
 		*ipap &= PMD_MASK;
 		kvm_release_pfn_clean(pfn);
 		pfn &= ~(PTRS_PER_PMD - 1);
-		kvm_get_pfn(pfn);
+		get_page(pfn_to_page(pfn));
 		*pfnp = pfn;
 
 		return PMD_SIZE;