KVM: nVMX: Drop redundant VMCS switch and free_nested() call

Remove the explicit switch to vmcs01 and the call to free_nested() in
nested_vmx_free_vcpu().  free_nested(), which is called unconditionally
by vmx_leave_nested(), ensures vmcs01 is loaded prior to freeing vmcs02
and friends.
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200923184452.980-7-sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx/nested.c

@@ -326,8 +326,6 @@ void nested_vmx_free_vcpu(struct kvm_vcpu *vcpu)
 {
 	vcpu_load(vcpu);
 	vmx_leave_nested(vcpu);
-	vmx_switch_vmcs(vcpu, &to_vmx(vcpu)->vmcs01);
-	free_nested(vcpu);
 	vcpu_put(vcpu);
 }