[libvirt] [PATCH] COW storage volume compile fix

[Markus Armbruster <armbru redhat com>]

Commit 2d4381d0 broke compilation for !HAVE_QEMU_IMG &&
HAVE_QCOW_CREATE.  Fix that.

Signed-off-by: Markus Armbruster <armbru redhat com>
---
Compile-tested only.

diff --git a/src/storage_backend_fs.c b/src/storage_backend_fs.c
index 345dc40..0280c45 100644
--- a/src/storage_backend_fs.c
+++ b/src/storage_backend_fs.c
@@ -1130,7 +1130,7 @@ virStorageBackendFileSystemVolCreate(virConnectPtr conn,
                                   vol->target.format);
             return -1;
         }
-        if (vol->target.backingStore != NULL) {
+        if (vol->backingStore.path != NULL) {
             virStorageReportError(conn, VIR_ERR_NO_SUPPORT,
                                   _("copy-on-write image not supported with "
                                     "qcow-create"));