Fix compiler warning on format string

[BrettDong]

I was getting compiler warnings on format string type mismatch:

[  6%] Building CXX object CMakeFiles/ClangBuildAnalyzer.dir/src/BuildEvents.cpp.o
/Users/brett/git/ClangBuildAnalyzer/src/BuildEvents.cpp:55:92: warning: format
      specifies type 'long' but the argument has type 'int64_t'
      (aka 'long long') [-Wformat]
  ...t1=%7ld t2=%7ld par=%4i ch=%4zi det=%s\n", i, (int) event.type, event.ts...
        ~~~~                                                         ^~~~~~~~
        %7lld
/Users/brett/git/ClangBuildAnalyzer/src/BuildEvents.cpp:55:102: warning: format
      specifies type 'long' but the argument has type 'long long' [-Wformat]
  ...%7ld par=%4i ch=%4zi det=%s\n", i, (int) event.type, event.ts, event.ts+event.dur...
     ~~~~                                                           ^~~~~~~~~~~~~~~~~~
     %7lld
2 warnings generated.

[aras-p]

Superseded by #80