media: usb: dvd-usb: fix uninit-value bug in dibusb_read_eeprom_byte()

In dibusb_read_eeprom_byte(), if dibusb_i2c_msg() fails, val gets
assigned an value that's not properly initialized.
Using kzalloc() in place of kmalloc() for the buffer fixes this issue,
as the val can now be set to 0 in the event dibusb_i2c_msg() fails.

Reported-by:  <syzbot+e27b4fd589762b0b9329@syzkaller.appspotmail.com>
Tested-by:  <syzbot+e27b4fd589762b0b9329@syzkaller.appspotmail.com>
Signed-off-by: Anant Thazhemadam <anant.thazhemadam@gmail.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>