fixup! recovery_utils: add support for unmounting entire volumes

Change-Id: I0cdb4b16047e9dac3a6d3c55ec8b91f582f24369
diff --git a/install/wipe_data.cpp b/install/wipe_data.cpp
index 6357aac..56d3674 100644
--- a/install/wipe_data.cpp
+++ b/install/wipe_data.cpp
@@ -93,7 +93,14 @@
     close(fd);
   }
 
-  if (ensure_volume_unmounted(vol->blk_device) == -1) {
+  std::string blk_device;
+
+  if (!android::base::Realpath(vol->blk_device, &blk_device)) {
+    PLOG(ERROR) << "Failed to convert \"" << vol->blk_device << "\" to absolute path";
+    return false;
+  }
+
+  if (ensure_volume_unmounted(blk_device) == -1) {
     PLOG(ERROR) << "Failed to unmount volume!";
     return false;
   }