download/grub: delete grub if gnulib cloning fails

for our purposes, grub and gnulib are one in the same

if one fails, both have failed

exit with non-zero status if gnulib fails

the script sets -e so it will fail if grub fails to
download, which is tried before gnulib, and if that
happens, the grub directory is not created

resources/scripts/download/grub

@@ -2,7 +2,8 @@
 
 #  helper script: Downloads GRUB and patches it.
 #
-#	Copyright (C) 2014, 2015, 2016, 2020, 2021 Leah Rowe <info@minifree.org>
+#	Copyright (C) 2014,2015,2016,2020,2021,2023 Leah Rowe
+#							<info@minifree.org>
 #
 #    This program is free software: you can redistribute it and/or modify
 #    it under the terms of the GNU General Public License as published by
@@ -22,4 +23,10 @@
 set -u -e
 
 ./gitclone grub
-./gitclone gnulib
+./gitclone gnulib || rm -Rf grub/
+if [ ! -d grub ]; then
+	printf "%s: Could not download grub and gnulib\n" ${0}
+	exit 1
+else
+	exit 0
+fi