hugetlb: remove meaningless BUG_ON(huge_pte_none())

When code reaches here, invalid page would have been accessed if huge pte
is none. So this BUG_ON(huge_pte_none()) is meaningless. Remove it.

Link: https://lkml.kernel.org/r/20220901120030.63318-10-linmiaohe@huawei.comSigned-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/hugetlb.c

@@ -5345,7 +5345,6 @@ static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma,
 			u32 hash;
 
 			put_page(old_page);
-			BUG_ON(huge_pte_none(pte));
 			/*
 			 * Drop hugetlb_fault_mutex and i_mmap_rwsem before
 			 * unmapping.  unmapping needs to hold i_mmap_rwsem