FROMGIT: kheaders: rename the 'cpio_dir' variable to 'tmpdir'

The next commit will get rid of the use of 'cpio' command, as there is
no strong reason to use it just for copying files.

Before that, this commit renames the 'cpio_dir' variable to 'tmpdir'.

No functional changes are intended.

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

Bug: 354775288
Bug: 368667510
Bug: 291611617
Change-Id: Ifccf20c43cefbed6eeecfec4eb12ca77ed2942bf
(cherry picked from commit 28186b227b316f5be2a9d7343f32e0457ffdd953
 https://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git for-next)
[elsk: Resolve minor merge conflict due to
 28fa7afc42 "FROMLIST: kheaders: dereferences the source tree".]
Signed-off-by: HONG Yifan <elsk@google.com>

kernel/gen_kheaders.sh

@@ -7,7 +7,7 @@ set -e
 sfile="$(readlink -f "$0")"
 outdir="$(pwd)"
 tarfile=$1
-cpio_dir=$outdir/${tarfile%/*}/.tmp_cpio_dir
+tmpdir=$outdir/${tarfile%/*}/.tmp_dir
 
 dir_list="
 include/
@@ -65,15 +65,15 @@ fi
 
 echo "  GEN     $tarfile"
 
-rm -rf $cpio_dir
-mkdir $cpio_dir
+rm -rf "${tmpdir}"
+mkdir "${tmpdir}"
 
 if [ "$building_out_of_srctree" ]; then
 	(
 		cd $srctree
 		for f in $dir_list
 			do find "$f" -name "*.h";
-		done | cpio --quiet -L -pd $cpio_dir
+		done | cpio --quiet -L -pd "${tmpdir}"
 	)
 fi
 
@@ -81,19 +81,19 @@ fi
 # of tree builds having stale headers in srctree. Just silence CPIO for now.
 for f in $dir_list;
 	do find "$f" -name "*.h";
-done | cpio --quiet -L -pdu $cpio_dir >/dev/null 2>&1
+done | cpio --quiet -L -pdu "${tmpdir}" >/dev/null 2>&1
 
 # Remove comments except SDPX lines
-find $cpio_dir -type f -print0 |
+find "${tmpdir}" -type f -print0 |
 	xargs -0 -P8 -n1 perl -pi -e 'BEGIN {undef $/;}; s/\/\*((?!SPDX).)*?\*\///smg;'
 
 # Create archive and try to normalize metadata for reproducibility.
 tar "${KBUILD_BUILD_TIMESTAMP:+--mtime=$KBUILD_BUILD_TIMESTAMP}" \
     --owner=0 --group=0 --sort=name --numeric-owner --mode=u=rw,go=r,a+X \
-    -I $XZ -cf $tarfile -C $cpio_dir/ . > /dev/null
+    -I $XZ -cf $tarfile -C "${tmpdir}/" . > /dev/null
 
 echo $headers_md5 > kernel/kheaders.md5
 echo "$this_file_md5" >> kernel/kheaders.md5
 echo "$(md5sum $tarfile | cut -d ' ' -f1)" >> kernel/kheaders.md5
 
-rm -rf $cpio_dir
+rm -rf "${tmpdir}"