kecec_select_boot: default to Y when setting new boot option

Next prompt will be to ensure GPG key is attached, which defaults
to Y, so default here as well for consistency

Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>

initrd/bin/kexec-select-boot

@@ -186,11 +186,12 @@ scan_options() {
 save_default_option() {
 	read \
 		-n 1 \
-		-p "Saving a default will modify the disk. Proceed? (y/n): " \
+		-p "Saving a default will modify the disk. Proceed? (Y/n): " \
 		default_confirm
 	echo
 
-	if [ "$default_confirm" = "y" ]; then
+	[ "$default_confirm" = "" ] && default_confirm="y"
+	if [[ "$default_confirm" = "y" || "$default_confirm" = "Y" ]]; then
 		if kexec-save-default \
 			-b "$bootdir" \
 			-d "$paramsdev" \