virsh: Fix vol-info's 'Type' output

We have a new vol type "dir" in addition to "file" and "block", but
virsh doesn't know it. Fix it.

Additionally, the patch lets virsh output "unknown" if not matched
any of them.

tools/virsh.c

@@ -9540,9 +9540,22 @@ cmdVolInfo(vshControl *ctl, const vshCmd *cmd)
     if (virStorageVolGetInfo(vol, &info) == 0) {
         double val;
         const char *unit;
-        vshPrint(ctl, "%-15s %s\n", _("Type:"),
-                 info.type == VIR_STORAGE_VOL_FILE ?
-                 _("file") : _("block"));
+        switch(info.type) {
+        case VIR_STORAGE_VOL_FILE:
+            vshPrint(ctl, "%-15s %s\n", _("Type:"), _("file"));
+            break;
+
+        case VIR_STORAGE_VOL_BLOCK:
+            vshPrint(ctl, "%-15s %s\n", _("Type:"), _("block"));
+            break;
+
+        case VIR_STORAGE_VOL_DIR:
+            vshPrint(ctl, "%-15s %s\n", _("Type:"), _("dir"));
+            break;
+
+        default:
+            vshPrint(ctl, "%-15s %s\n", _("Type:"), _("unknown"));
+        }
 
         val = prettyCapacity(info.capacity, &unit);
         vshPrint(ctl, "%-15s %2.2lf %s\n", _("Capacity:"), val, unit);