xen: close evtchn port if binding to irq fails

commit e7e44e444876478d50630f57b0c31d29f6725020 upstream.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>