fix show delete list in dry run mode

btrfs-snapshots.sh

@@ -101,6 +101,10 @@ for fs in ${BTRFS_VOLUMES}; do
     date="-$(date +%Y-%m-%d-%H-%M)"
     target="${name}snapshot${periodity}"
     if test -n "$device"; then
+        if mount | grep -q " on $TMP_MNT type "; then
+            sudo umount "$TMP_MNT"
+        fi
+        sudo mount "$device" "$TMP_MNT"
         if test $dryrun -eq 1; then
             echo -e "→ \e[1mbackup ${subvol:+subvol $subvol of }$fs on $device\e[0m"
             echo " " mount "$device" "$TMP_MNT"
@@ -112,18 +116,14 @@ for fs in ${BTRFS_VOLUMES}; do
             fi
             echo " " umount "$TMP_MNT"
         else
-            if mount | grep -q " on $TMP_MNT type "; then
-                sudo umount "$TMP_MNT"
-            fi
-            sudo mount "$device" "$TMP_MNT"
             sudo btrfs subvolume snapshot "${TMP_MNT}${subvol}" "${TMP_MNT}${target}${date}"
             #if test -n "$del"; then
             #    for f in $(ls -1 "${TMP_MNT}${target}${date}"-* | tail -n +"$del"); do
             #        sudo btrfs subvolume delete "$f"
             #    done
             #fi
-            sudo umount "$TMP_MNT"
         fi
+        sudo umount "$TMP_MNT"
     else
         echo "ERROR: no device found for $fs" 1>&2
         exit 2