The yam_ioctl() code fails to initialise the cmd field
of the struct yamdrv_ioctl_cfg. Add an explicit memset(0)
before filling the structure to avoid the 4-byte info leak.
Signed-off-by: Salva Peiró <speiro@ai2.upv.es> Signed-off-by: David S. Miller <davem@davemloft.net>