Clean up temporary files and directories left by build_image, etc.

src/scripts/build_image

Index: src/scripts/build_image
diff --git a/src/scripts/build_image b/src/scripts/build_image
index dbe62a74be21b308045950d7ebe9d622781f6ff4..b6b665a6b56d2036d025334e6140f2192e8222f6 100755
--- a/src/scripts/build_image
+++ b/src/scripts/build_image
@@ -69,7 +69,6 @@ IMAGE_SUBDIR="${CHROMEOS_VERSION_STRING}-a${FLAGS_build_attempt}"
 OUTPUT_DIR="${FLAGS_output_root}/${FLAGS_board}/${IMAGE_SUBDIR}"
 ROOT_FS_DIR="${OUTPUT_DIR}/rootfs"
 ROOT_FS_IMG="${OUTPUT_DIR}/rootfs.image"
-MBR_IMG="${OUTPUT_DIR}/mbr.image"
 OUTPUT_IMG="${OUTPUT_DIR}/chromiumos_image.bin"
 
 BOARD="${FLAGS_board}"
@@ -323,7 +322,7 @@ fi
 # Extract the kernel from the root filesystem for use by the GPT image. Legacy
 # BIOS will use the kernel in the rootfs (via syslinux), ChromeOS BIOS will use
 # the kernel partition.
-sudo cp -f ${ROOT_FS_DIR}/boot/vmlinuz ${OUTPUT_DIR}/vmlinuz.image
+sudo cp -f "${ROOT_FS_DIR}/boot/vmlinuz" "${OUTPUT_DIR}/vmlinuz.image"
 
 #TODO(sosa@chromium.org) - Does it make sense to leave /usr/local bound here?
 "${SCRIPTS_DIR}/customize_rootfs" \
@@ -355,8 +354,11 @@ cleanup_rootfs_loop
 # Create the GPT-formatted image
 ${SCRIPTS_DIR}/build_gpt.sh \
    --arch=${ARCH} --board=${FLAGS_board} --board_root=${BOARD_ROOT} \
-   ${OUTPUT_DIR} ${OUTPUT_IMG}
+   "${OUTPUT_DIR}" "${OUTPUT_IMG}"
 
+# Clean up temporary files.
+rm -f "${ROOT_FS_IMG}" "${STATEFUL_IMG}" "${OUTPUT_DIR}/vmlinuz.image"
+rmdir "${ROOT_FS_DIR}" "${STATEFUL_DIR}"
 
 OUTSIDE_OUTPUT_DIR="../build/images/${FLAGS_board}/${IMAGE_SUBDIR}"
 echo "Done.  Image created in ${OUTPUT_DIR}"