usb: typec: wcove: fix uninitialized usbc_irq1 and usbc_irq2

Calls to regmap_read may fail with an -EINVAL return without setting
usbc_irq1 and usbc_irq2.  The error handling clean up expects these
to have been set (or zero on a failure) and currently may try to
clear the wrong IRQs if the uninitalized garbage values in usbc_irq1
or usbc_irq2 are non-zero.  The simplest fix is to ensure these
variables are initialized to zero.

Detected by CoverityScan, CID#1457737 ("Uninitialized scalar variable")

Fixes: 3c4fb9f1

 ("usb: typec: wcove: start using tcpm for USB PD support")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>