KVM: x86: mmu: initialize fault.async_page_fault in walk_addr_generic

This field was left uninitialized by a mistake.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210225154135.405125-3-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/mmu/paging_tmpl.h

@@ -503,6 +503,7 @@ static int FNAME(walk_addr_generic)(struct guest_walker *walker,
 #endif
 	walker->fault.address = addr;
 	walker->fault.nested_page_fault = mmu != vcpu->arch.walk_mmu;
+	walker->fault.async_page_fault = false;
 
 	trace_kvm_mmu_walker_error(walker->fault.error_code);
 	return 0;