Since the beginning, charged is set to 0 to avoid calling vm_unacct_memory
twice because vm_unacct_memory will be called by above unmap_region.  But
since commit 
4f74d2c8e827 ("vm: remove 'nr_accounted' calculations from
the unmap_vmas() interfaces"), unmap_region doesn't call vm_unacct_memory
anymore.  So charged shouldn't be set to 0 now otherwise the calling to
paired vm_unacct_memory will be missed and leads to imbalanced account.
Link: https://lkml.kernel.org/r/20220618082027.43391-1-linmiaohe@huawei.com
Fixes: 4f74d2c8e827 ("vm: remove 'nr_accounted' calculations from the unmap_vmas() interfaces")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 
        /* Undo any partial mapping done by a device driver. */
        unmap_region(mm, vma, prev, vma->vm_start, vma->vm_end);
-       charged = 0;
        if (vm_flags & VM_SHARED)
                mapping_unmap_writable(file->f_mapping);
 free_vma: