Merge branch 'maint'

* maint:
Fix non-literal format in printf-style calls
git-submodule: Avoid printing a spurious message.
git ls-remote: make usage string match manpage
Makefile: help people who run 'make check' by mistake

diff --cc Makefile
Simple merge

diff --cc builtin-remote.c
Simple merge

diff --cc environment.c
Simple merge

diff --cc fsck.c
Simple merge

diff --cc git-submodule.sh
Simple merge

diff --cc grep.c
Simple merge

diff --cc refs.c
Simple merge