Summary:
Previously, the trace_analyzer_tool will be complied with other libobjects, which let the GFLAGS of trace_analyzer appear in other tools (e.g., db_bench, rocksdb_dump, and etc.). When using '--help', the help information of trace_analyzer will appear in other tool help information, which will cause confusion issues.

Currently, trace_analyzer_tool is built and used only by trace_analyzer and trace_analyzer_test to avoid the issues.

Tested with make asan_check.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4290

Differential Revision: D9413163

Pulled By: zhichao-cao

fbshipit-source-id: ed5d20c4575a53ca15ff62a2ffe601d5cf278cc4