Use 'umount -nR' regardless of OS

zfs.sh

@@ -222,13 +222,9 @@ if [[ "${1}" == '--key' ]]; then
 fi
 
 if [[ "${1}" == '--unmount' ]]; then
-	mount | grep -v zfs | tac | awk '/\/mnt/ {print $3}' | xargs -I {} umount -lf {}
-
-	if [[ "${ID}" == 'fedora' ]]; then
-		umount \
-			-nR \
-			/mnt
-	fi
+	umount \
+		-nR \
+		/mnt
 
 	zpool \
 		export \