gen_initramfs.sh: remove intermediate cpio_list on errors

This script sets the -e option, so it exits on any error, in which
case it exits without cleaning up the intermediate cpio_list.

Make sure to delete it on exit.
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

usr/gen_initramfs.sh

@@ -193,6 +193,8 @@ dep_list=
 cpio_list=$(mktemp ${TMPDIR:-/tmp}/cpiolist.XXXXXX)
 output="/dev/stdout"
 
+trap "rm -f $cpio_list" EXIT
+
 while [ $# -gt 0 ]; do
 	arg="$1"
 	shift
@@ -243,4 +245,3 @@ if test -n "$KBUILD_BUILD_TIMESTAMP"; then
 	fi
 fi
 usr/gen_init_cpio $timestamp $cpio_list > $output
-rm $cpio_list