isdn: mISDN: Fix sleeping function called from invalid context
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 v5.15 by commit 6510e80a0b81b5d814e3aea6297ba42f5e76f73c. For more details please see the references link.