[LNT] Fixed the time extraction from MMAP and MMAP2 events using the Layout

We used a lot of perf_data files from different systems to analyze, summarize and debug the time extraction from MMAP and MMAP2 events.

OS Laboratory. Huawei Russian Research Institute. Saint-Petersburg

Reviewed By: thopre

Differential Revision: https://reviews.llvm.org/D117008