KVM: VMX: avoid guest hang on invalid invept instruction

A guest executing an invalid invept instruction would hang
because the instruction pointer was not updated.

Cc: stable@vger.kernel.org
Fixes: bfd0a56b


Reviewed-by: David Matlack <dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>