Merge "fs_mgr: overlayfs: CreateDynamicScratch for *partition_exists" am: 684122a264

Change-Id: I02520fe874e0ba5adefeb597acd31b401e635563
diff --git a/fs_mgr/fs_mgr_overlayfs.cpp b/fs_mgr/fs_mgr_overlayfs.cpp
index 2bc53d3..1fa1aa1 100644
--- a/fs_mgr/fs_mgr_overlayfs.cpp
+++ b/fs_mgr/fs_mgr_overlayfs.cpp
@@ -1026,6 +1026,8 @@
         }
 
         if (change) *change = true;
+    } else if (scratch_device->empty()) {
+        *scratch_device = GetBootScratchDevice();
     }
     return true;
 }