'migrate_vma_{setup,pages,finalize}()' functions are defined under
CONFIG_DEVICE_PRIVATE, but their declarations are not.  This commit
wraps the declaration under the config to minimize confusion.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 include/linux/migrate.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index 66a34eae8cb6..f8fa7db83e23 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -162,9 +162,14 @@ struct migrate_vma {
 	unsigned long		flags;
 };
 
+#ifdef CONFIG_DEVICE_PRIVATE
+
 int migrate_vma_setup(struct migrate_vma *args);
 void migrate_vma_pages(struct migrate_vma *migrate);
 void migrate_vma_finalize(struct migrate_vma *migrate);
+
+#endif /* CONFIG_DEVICE_PRIVATE */
+
 int next_demotion_node(int node);
 
 #else /* CONFIG_MIGRATION disabled: */
-- 
2.17.1