GSD-2022-1000607 ceph: properly put ceph_string reference after async create attempt

properly put ceph_string reference after async create attempt. 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 v5.16.5 by commit a0c22e970cd78b81c94691e6cb09713e8074d580, it was introduced in version v5.7 by commit 9a8d03ca2e2c334d08ee91a3e07dcce31a02fdc6. For more details please see the references link