Merge branch 'jk/format-patch-leakfix' into jch

A memory leak in the '--base' handling of 'git format-patch' has been
plugged, and the leak-reporting of the test suite when running under a
TAP harness has been improved.

* jk/format-patch-leakfix:
  format-patch: fix leak of rev_info in prepare_bases()
  t: move LSan errors from stdout to stderr

diff --cc builtin/log.c
Simple merge

diff --cc t/test-lib.sh
Simple merge