xen/events: remove redundant initialization of variable irq

The variable irq is being initialized with a value that is never
read, it is being updated later on. The assignment is redundant and
can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20210721114010.108648-1-colin.king@canonical.com


Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>