CVE-2022-50334 hugetlbfs: fix null-ptr-deref in hugetlbfs_parse_param()

In the Linux kernel, the following vulnerability has been resolved: hugetlbfs: fix null-ptr-deref in hugetlbfsparseparam Syzkaller reports a null-ptr-deref bug as follows: ====================================================== KASAN: null-ptr-deref in range 0x0000000000000000-0x0000000000000007...