staging: kpc2000: Fix a stack information leak in kp2000_cdev_ioctl()

The kp2000_regs struct has a 4 byte hole between ->hw_rev and ->ssid so
this could leak stack information to the user.  This patch just memsets
the whole struct to zero.

Fixes: 7dc7967f ("staging: kpc2000: add initial set of Daktronics drivers")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/kpc2000/kpc2000/fileops.c

@@ -91,6 +91,8 @@ long  kp2000_cdev_ioctl(struct file *filp, unsigned int ioctl_num, unsigned long
 	case KP2000_IOCTL_GET_EVERYTHING: {
 		struct kp2000_regs temp;
 		int ret;
+
+		memset(&temp, 0, sizeof(temp));
 		temp.card_id = pcard->card_id;
 		temp.build_version = pcard->build_version;
 		temp.build_datestamp = pcard->build_datestamp;