fix several shellcheck warnings

lbmk didn't quote certain arguments in commands, or
used ! -z instead of -n, things like that. simple fixes.

Signed-off-by: Leah Rowe <leah@libreboot.org>

script/build/grub

@@ -45,7 +45,7 @@ build_keymap_configs()
 {
 	for keylayoutfile in "${grubcfgsdir}/keymap/"*.gkb; do
 		[ -f "${keylayoutfile}" ] || continue
-		keymap="${keylayoutfile##${grubcfgsdir}/keymap/}"
+		keymap="${keylayoutfile##"${grubcfgsdir}/keymap/"}"
 		keymap="${keymap%.gkb}"
 		printf "keymap %s\n" "${keymap}" > \
 		    "${elfdir}/keymap_${keymap}.cfg" || err "!insert keymap"

script/build/roms

@@ -64,7 +64,7 @@ main()
 
 	[ -z "${targets}" ] && err "No ROM images were compiled"
 	printf "\nROM images available in these directories:\n"
-	printf "${targets}^^ ROM images available in these directories.\n\n"
+	printf "%s^^ ROM images available in these directories.\n\n" "${targets}"
 
 	printf "DO NOT flash ROM images from elf/ - please use bin/ instead.\n"
 }
@@ -230,7 +230,7 @@ build_roms()
 
 	_cbrom="elf/coreboot_nopayload_DO_NOT_FLASH/${board}/${initmode}_${displaymode}"
 	[ "${initmode}" = "normal" ] && \
-		_cbrom="${_cbrom%_${displaymode}}"
+		_cbrom="${_cbrom%"_${displaymode}"}"
 	_cbrom="${_cbrom}/coreboot.rom"
 	cbrom="$(mktemp -t coreboot_rom.XXXXXXXXXX)"
 	x_ cp "${_cbrom}" "${cbrom}"
@@ -349,7 +349,7 @@ mkSeabiosRom() {
 
 	x_ cp "${_cbrom}" "${tmprom}"
 	x_ "${cbfstool}" "${tmprom}" add-payload -f "${_seabioself}" \
-	    -n ${_seabios_cbfs_path} -c lzma
+	    -n "${_seabios_cbfs_path}" -c lzma
 	x_ "${cbfstool}" "${tmprom}" add-int -i 3000 -n etc/ps2-keyboard-spinup
 
 	z="2"; [ "${initmode}" = "vgarom" ] && z="0"
@@ -405,7 +405,7 @@ mkUbootRom() {
 
 	x_ cp "${_cbrom}" "${tmprom}"
 	x_ "${cbfstool}" "${tmprom}" add-payload -f "${_ubootelf}" \
-	    -n ${_uboot_cbfs_path} -c lzma
+	    -n "${_uboot_cbfs_path}" -c lzma
 
 	printf "%s\n" "${tmprom}"
 }

script/build/serprog

@@ -50,24 +50,24 @@ main()
 build_rp2040_rom()
 {
 	board=${1}
-	printf "Building pico-serprog for ${board}\n"
+	printf "Building pico-serprog for %s\n" "${board}"
 	x_ cmake -DPICO_BOARD="${board}" -DPICO_SDK_PATH="${pico_sdk_dir}" \
 	    -B "${pico_src_dir}/build" "${pico_src_dir}"
 	x_ cmake --build "${pico_src_dir}/build"
 	x_ mv ${pico_src_dir}/build/pico_serprog.uf2 \
 	   bin/serprog_rp2040/serprog_${board}.uf2
-	printf "output to bin/serprog_rp2040/serprog_${board}.uf2\n"
+	printf "output to bin/serprog_rp2040/serprog_%s.uf2\n" "${board}"
 }
 
 build_stm32_rom()
 {
 	board=${1}
-	printf "Building stm32-vserprog for ${board}\n"
+	printf "Building stm32-vserprog for %s\n" "${board}"
 	x_ make -C ${stm32_src_dir} libopencm3-just-make BOARD=${board}
 	x_ make -C ${stm32_src_dir} BOARD=${board}
 	x_ mv ${stm32_src_dir}/stm32-vserprog.hex \
 	   bin/serprog_stm32/serprog_${board}.hex
-	printf "output to bin/serprog_stm32/serprog_${board}.hex\n"
+	printf "output to bin/serprog_stm32/serprog_%s.hex\n" "${board}"
 }
 
 print_boards()
@@ -78,7 +78,7 @@ print_boards()
 
 list_boards()
 {
-	basename -a -s .h ${1}/*.h
+	basename -a -s .h "${1}/"*.h
 }
 
 main $@