ubifs: Free memory for tmpfile name

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

ubifs: Free memory for tmpfile name

When opening a ubifs tmpfile on an encrypted directory, function fscrypt_setup_filename allocates memory for the name that is to be stored in the directory entry, but after the name has been copied to the directory entry inode, the memory is not freed.

When running kmemleak on it we see that it is registered as a leak. The report below is triggered by a simple program 'tmpfile' just opening a tmpfile:

unreferenced object 0xffff88810178f380 (size 32): comm "tmpfile", pid 509, jiffies 4294934744 (age 1524.742s) backtrace: __kmem_cache_alloc_node __kmalloc fscrypt_setup_filename ubifs_tmpfile vfs_tmpfile path_openat

Free this memory after it has been copied to the inode.