KVM: MMU: propagate alloc_workqueue failure

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2074832



commit a1a39128
Author: Paolo Bonzini <pbonzini@redhat.com>
Date:   Fri Mar 25 12:42:52 2022 -0400

    KVM: MMU: propagate alloc_workqueue failure

    If kvm->arch.tdp_mmu_zap_wq cannot be created, the failure has
    to be propagated up to kvm_mmu_init_vm and kvm_arch_init_vm.
    kvm_arch_init_vm also has to undo all the initialization, so
    group all the MMU initialization code at the beginning and
    handle cleaning up of kvm_page_track_init.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>