Pull Kbuild fixes from Masahiro Yamada:
- fix O= building on dash
- remove unused dependency in Makefile
- fix default of a choice in Kconfig
- fix typos and documentation style
- fix command options unrecognized by sparse
* tag 'kbuild-fixes-v4.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: clang: fix build failures with sparse check
kbuild doc: a bundle of fixes on makefiles.txt
Makefile: kselftest: fix grammar typo
kbuild: Fix optimization level choice default
kbuild: drop unused symverfile in Makefile.modpost
kbuild: revert $(realpath ...) to $(shell cd ... && /bin/pwd)