KVM: nVMX: Free the VMREAD/VMWRITE bitmaps if alloc_kvm_area() fails

Fixes: 34a1cd60 ("kvm: x86: vmx: move some vmx setting from vmx_init() to hardware_setup()")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>