btrfs: fix uninitialized pointer free on read_alloc_one_name() error

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix uninitialized pointer free on read_alloc_one_name() error The function read_alloc_one_name() does not initialize the name field of the passed fscrypt_str struct if kmalloc fails to allocate the corresponding buffer. Thus, it is not guaranteed that fscrypt_str.name is initialized when freeing it. This is a follow-up to the linked patch that fixes the remaining instances of the bug introduced by commit e43eec81c516 ("btrfs: use struct qstr instead of name and namelen pairs").