Created function xdt_unmount from xdt_write_image

xorriso-dd-target/xorriso-dd-target.xdt

@@ -650,6 +650,40 @@ xdt_list_mounted_of() {
   return 0
 }
 
+## Unmount xdt_mounted_devs (maybe filled by xdt_list_mounted_of)
+xdt_unmount() {
+  if test -z "$xdt_mounted_devs"
+  then
+    return 0
+  fi
+
+  for xdt_i in $xdt_mounted_devs
+  do
+    if test -n "$xdt_dummy_run"
+    then
+      echo "  $xdt_sudo_cmd $xdt_umount_cmd $xdt_i"
+    elif $xdt_sudo_cmd "$xdt_umount_cmd" "$xdt_i"
+    then
+      echo "Unmounted: $xdt_i"
+    else
+      echo "FAILURE: Non-zero exit value with:  $xdt_sudo_cmd $xdt_umount_cmd $xdt_i" >&2
+      return 7
+    fi
+  done
+
+  # Check again if any mount points still exist
+  if test -z "$xdt_dummy_run"
+  then
+    xdt_list_mounted_of "$2"
+    if test -n "$xdt_mounted_devs"
+    then
+      echo "FAILURE: $xdt_sudo_cmd $xdt_umount_cmd could not remove all mounts: $xdt_mounted_devs" >&2
+      return 7
+    fi
+  fi
+  return 0
+}
+
 ## Does the work of unmounting and dd-ing
 xdt_write_image() {
 
@@ -670,35 +704,8 @@ xdt_write_image() {
   then
     echo "Would do if not -dummy:"
   fi
-  if test -n "$xdt_mounted_devs"
-  then
-    for xdt_i in $xdt_mounted_devs
-    do
-      if test -n "$xdt_dummy_run"
-      then
-        echo "  $xdt_sudo_cmd $xdt_umount_cmd $xdt_i"
-      else
-        if $xdt_sudo_cmd "$xdt_umount_cmd" "$xdt_i"
-        then
-          echo "Unmounted: $xdt_i"
-        else
-          echo "FAILURE: Non-zero exit value with:  $xdt_sudo_cmd $xdt_umount_cmd $xdt_i" >&2
-          return 7
-        fi
-      fi
-    done
 
-    # Check again if any mount points still exist
+  xdt_unmount || return "$?"
-    if test -z "$xdt_dummy_run"
-    then
-      xdt_list_mounted_of "$2"
-      if test -n "$xdt_mounted_devs"
-      then
-        echo "FAILURE: $xdt_sudo_cmd $xdt_umount_cmd could not remove all mounts: $xdt_mounted_devs" >&2
-        return 7
-      fi
-    fi
-  fi
 
   if test -z "$xdt_dd_cmd"
   then