Merge branch 'mt/checkout-count-fix'

"git checkout" miscounted the paths it updated, which has been
corrected.
source: <redacted>

* mt/checkout-count-fix:
  checkout: fix two bugs on the final count of updated entries
  checkout: show bug about failed entries being included in final report
  checkout: document bug where delayed checkout counts entries twice

diff --cc builtin/checkout.c
Simple merge