CVE-2023-53826 ubi: Fix UAF wear-leveling entry in eraseblk_count_seq_show()

In the Linux kernel, the following vulnerability has been resolved: ubi: Fix UAF wear-leveling entry in eraseblkcountseqshow Wear-leveling entry could be freed in error path, which may be accessed again in eraseblkcountseqshow, for example: eraseworker eraseblkcountseqshow wl =...