net: usb: smsc75xx: Fix uninit-value access in __smsc75xx_read_reg
JIRA: https://issues.redhat.com/browse/RHEL-28017
CVE: CVE-2023-52528
net: usb: smsc75xx: Fix uninit-value access in __smsc75xx_read_reg
Signed-off-by: Jose Ignacio Tornos Martinez jtornosm@redhat.com