CVE-2025-38195 LoongArch: Fix panic caused by NULL-PMD in huge_pte_offset()

In the Linux kernel, the following vulnerability has been resolved: LoongArch: Fix panic caused by NULL-PMD in hugepteoffset ERROR INFO: CPU 25 Unable to handle kernel paging request at virtual address 0x0 ... Call Trace: hugepteoffset+0x3c/0x58 hugetlbfollowpagemask+0x74/0x438...