CVE-2023-53381

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

NFSD: fix leaked reference count of nfsd4_ssc_umount_item

The reference count of nfsd4_ssc_umount_item is not decremented
on error conditions. This prevents the laundromat from unmounting
the vfsmount of the source file.

This patch decrements the reference count of nfsd4_ssc_umount_item
on error.