ntfs: detect mapping-pairs LCN accumulator overflow

In the Linux kernel, the following vulnerability has been resolved:

ntfs: detect mapping-pairs LCN accumulator overflow

The NTFS mapping-pairs parser accumulates relative LCN deltas in a
signed integer. A corrupted attribute can drive that addition past
the representable range.

One corrupt runlist shape sets the accumulated LCN to S64_MAX and
then adds a delta of 1 in the next mapping-pairs entry.

Signed overflow is undefined and can turn an invalid runlist into a
different set of physical clusters.

Check the LCN addition for overflow before storing the next run.