kbuild: move W=1 check for scripts/misc-check to top-level Makefile

This script is executed only when ${KBUILD_EXTRA_WARN} contains 1.
Move this check to the top-level Makefile to allow more checks to be
easily added to this script.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>

scripts/misc-check

@@ -3,15 +3,8 @@
 
 set -e
 
-# Detect files that are tracked but ignored by git. This is checked only when
-# ${KBUILD_EXTRA_WARN} contains 1, git is installed, and the source tree is
-# tracked by git.
+# Detect files that are tracked but ignored by git.
 check_tracked_ignored_files () {
-	case "${KBUILD_EXTRA_WARN}" in
-	*1*) ;;
-	*) return;;
-	esac
-
 	git -C ${srctree:-.} ls-files -i -c --exclude-per-directory=.gitignore 2>/dev/null |
 		sed 's/$/: warning: ignored by one of the .gitignore files/' >&2
 }