Merge tag 'kbuild-fixes-v4.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:
 "Nothing scary, just some random fixes:

   - fix warnings of host programs

   - fix "make tags" when COMPILED_SOURCE=1 is specified along with O=

   - clarify help message of C=1 option

   - fix dependency for ncurses compatibility check

   - fix "make headers_install" for fakechroot environment"

* tag 'kbuild-fixes-v4.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kconfig: fix sparse warnings in nconfig
  kbuild: fix header installation under fakechroot environment
  kconfig: Check for libncurses before menuconfig
  Kbuild: tiny correction on `make help`
  tags: honor COMPILED_SOURCE with apart output directory
  genksyms: add printf format attribute to error_with_pos()