scripts/misc-check: add double-quotes to satisfy shellcheck

In scripts/misc-check line 8:
        git -C ${srctree:-.} ls-files -i -c --exclude-per-directory=.gitignore 2>/dev/null |
               ^-----------^ SC2086 (info): Double quote to prevent globbing and word splitting.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Author: masahir0y

scripts/misc-check

@@ -5,7 +5,7 @@ set -e
 
 # Detect files that are tracked but ignored by git.
 check_tracked_ignored_files () {
-	git -C ${srctree:-.} ls-files -i -c --exclude-per-directory=.gitignore 2>/dev/null |
+	git -C "${srctree:-.}" ls-files -i -c --exclude-per-directory=.gitignore 2>/dev/null |
 		sed 's/$/: warning: ignored by one of the .gitignore files/' >&2
 }