comedi: ni_usb6501: fix NULL-deref in command paths
This is an automated ID intended to aid in discovery of potential security vulnerabilities. The actual impact and attack plausibility have not yet been proven. This ID is fixed in Linux Kernel version v4.4.292 by commit 58478143771b20ab219937b1c30a706590a59224, it was introduced in version v3.18 by commit a03bb00e50ab4c07107da58a52a0bff7943f360c. For more details please see the references link.