Disks are always block devices, never character devices

The LXC disk hotplug code was allowing block or character devices
to be given as disk. A disk is always a block device.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>
(cherry picked from commit d24e6b8b)

src/lxc/lxc_driver.c

@@ -3061,9 +3061,9 @@ lxcDomainAttachDeviceDiskLive(virLXCDriverPtr driver,
         goto cleanup;
     }
 
-    if (!S_ISCHR(sb.st_mode) && !S_ISBLK(sb.st_mode)) {
+    if (!S_ISBLK(sb.st_mode)) {
         virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
-                       _("Disk source %s must be a character/block device"),
+                       _("Disk source %s must be a block device"),
                        def->src);
         goto cleanup;
     }
@@ -3075,11 +3075,7 @@ lxcDomainAttachDeviceDiskLive(virLXCDriverPtr driver,
     if (VIR_REALLOC_N(vm->def->disks, vm->def->ndisks+1) < 0)
         goto cleanup;
 
-    mode = 0700;
-    if (S_ISCHR(sb.st_mode))
-        mode |= S_IFCHR;
-    else
-        mode |= S_IFBLK;
+    mode = 0700 | S_IFBLK;
 
     /* Yes, the device name we're creating may not
      * actually correspond to the major:minor number