use the new coding style in scripts

there were stragglers left over from the last audit,
and these stragglers still exist even after all the
major re-factoring as of late

the new style is: bsd-like coding style and error
handling. verbose yet simple error handling. we use
an "err" function in a way reminiscent of most C
programs that you see in openbsd base (err.h)

this style is very clean, resulting in readable code

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

resources/scripts/build/grub/payload

@@ -21,6 +21,8 @@
 [ "x${DEBUG+set}" = 'xset' ] && set -v
 set -u -e
 
+. "include/err.sh"
+
 grubcfgsdir="resources/grub"
 keymap=""
 
@@ -30,26 +32,29 @@ main()
 {
 	printf "Creating GRUB payloads and configuration files\n"
 
-	[ ! -d "grub/" ] && \
-		./fetch grub
-	[ ! -f "grub/grub-mkstandalone" ] && \
-		./build grub utils
-	[ ! -d "elf/" ] && \
-		mkdir -p elf/
-	[ ! -d "elf/grub" ] && \
-		mkdir -p elf/grub/
-
-	rm -f elf/grub/*
+	handle_dependencies
 
 	# Separate GRUB payload per keymap to save space in ROM.
-
 	for keylayoutfile in ${grubcfgsdir}/keymap/*.gkb; do
+		[ -f "${keylayoutfile}" ] || continue
 		build_grub_payloads "${keylayoutfile}"
 	done
 
 	printf "Done! Check elf/grub/ to see the files.\n\n"
 }
 
+handle_dependencies()
+{
+	[ -d "grub/" ] || \
+		./fetch grub || err "cannot fetch grub"
+	[ -f "grub/grub-mkstandalone" ] || \
+		./build grub utils || err "cannot build grub utils"
+	[ -d "elf/grub" ] || \
+		mkdir -p elf/grub || err "cannot create directory, elf/grub"
+
+	rm -f elf/grub/* || err "cannot delete files in directory, elf/grub/"
+}
+
 build_grub_payloads()
 {
 	keylayoutfile=${1}
@@ -79,15 +84,16 @@ build_grub_elf()
 	    --fonts= --themes= --locales=  \
 	    --modules="${grub_modules}" \
 	    --install-modules="${grub_install_modules}" \
-	    ${gcfg} ${grubk}
+	    ${gcfg} ${grubk} || \
+	    err "cannot create grub payload (grub-mkstandalone)"
 }
 
 create_grub_config()
 {
 	sed "s/usqwerty/${keymap}/" < ${grubcfgsdir}/config/grub.cfg \
-	    > elf/grub/grub_${keymap}.cfg
+	    > elf/grub/grub_${keymap}.cfg || err "sed failed: grub.cfg"
 	sed "s/grubtest.cfg/grub.cfg/" < elf/grub/grub_${keymap}.cfg \
-	    > elf/grub/grub_${keymap}_test.cfg
+	    > elf/grub/grub_${keymap}_test.cfg || err "sed failed: grubtest.cfg"
 }
 
 main $@