avoid heredocs, they don't work on a fully readonly VFS

rc.in

@@ -33,8 +33,7 @@ rc.tmpdirs() {
 
 rc.mount_misc() {
 	for m in "${cfg_mounts[@]}"; do
-		IFS=':' read fs fs_type mountpoint mount_options <<< "$m"
-
+		echo "$m" | while IFS=':' read fs fs_type mountpoint mount_options; do
 			[[ "$mount_options" ]] || { mount_options='defaults'; }
 
 			mountpoint -q "$mountpoint" || {
@@ -42,6 +41,7 @@ rc.mount_misc() {
 				mount "$fs" -n -t "$fs_type" -o "$mount_options" "$mountpoint"
 			}
 		done
+	done
 }
 
 rc.parse_cmdline() {