staging: dgrp: info leak in dgrp_dpa_ioctl()

If "nd->nd_vpd_len" is less than 512 then the last part of the
"vpd.vpd_data" has uninitialized stack information.  We need to clear it
before copying the buffer to user space.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/dgrp/dgrp_dpa_ops.c

@@ -432,6 +432,7 @@ static long dgrp_dpa_ioctl(struct file *file, unsigned int cmd,
 
 
 	case DIGI_GETVPD:
+		memset(&vpd, 0, sizeof(vpd));
 		if (nd->nd_vpd_len > 0) {
 			vpd.vpd_len = nd->nd_vpd_len;
 			memcpy(&vpd.vpd_data, &nd->nd_vpd, nd->nd_vpd_len);