Merge branch 'ab/perf-installed-fix'

Performance test framework has been broken and measured the version of Git that happens to be on $PATH, not the specified one to measure, for a while, which has been corrected. * ab/perf-installed-fix: perf-lib.sh: forbid the use of GIT_TEST_INSTALLED perf tests: add "bindir" prefix to git tree test results perf-lib.sh: remove GIT_TEST_INSTALLED from perf-lib.sh perf-lib.sh: make "./run <revisions>" use the correct gits perf aggregate: remove GIT_TEST_INSTALLED from --codespeed perf README: correct docs for 3c8f12c96c regression