rust: hpet: fix new warning

Nightly rustc complains that HPETAddrDecode has a lifetime but it is not
clearly noted that it comes from &self.  Apply the compiler's suggestion
to shut it up.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
1 file changed