iommu/intel: Fix out-of-bounds memset in dmar_latency_disable()

In the Linux kernel, the following vulnerability has been resolved: iommu/intel: Fix out-of-bounds memset in dmar_latency_disable() dmar_latency_disable() intends to zero out only the single latency_statistic entry for the given type, but the memset size was computed as sizeof(*lstat) * DMAR_LATENCY_NUM, which clears the entire array starting from &lstat[type]. When type > 0, this writes beyond the end of the allocated array, corrupting adjacent memory. Fix by using sizeof(*lstat) to clear only the target entry.