rego-tunnel: relax qcow2 root detection

apps/rego-tunnel/build/start-vm.sh

@@ -51,7 +51,7 @@ if [ "$AUTO_MOUNT_9P" = "1" ]; then
 			[ -e "$part" ] || continue
 			# Try mount and detect a Linux root by presence of /etc/fstab and /etc/os-release
 			if mount "$part" "$VMROOT_MNT" >/dev/null 2>&1; then
-				if [ -f "$VMROOT_MNT/etc/fstab" ] && [ -f "$VMROOT_MNT/etc/os-release" ]; then
+				if [ -d "$VMROOT_MNT/etc" ] && { [ -f "$VMROOT_MNT/etc/os-release" ] || [ -f "$VMROOT_MNT/usr/lib/os-release" ] || [ -f "$VMROOT_MNT/usr/share/os-release" ]; }; then
 					ROOT_PART="$part"
 					break
 				fi