CVE-2024-56564

In the Linux kernel, the following vulnerability has been resolved:

ceph: pass cred pointer to ceph_mds_auth_match()

This eliminates a redundant get_current_cred() call, because
ceph_mds_check_access() has already obtained this pointer.

As a side effect, this also fixes a reference leak in
ceph_mds_auth_match(): by omitting the get_current_cred() call, no
additional cred reference is taken.