fs/bfs: Fix memory leak in read_bfs_file()

The l1_entries and l2_entries were not freed at the end of file read.

Fixes: 5825b3794 (BFS implementation based on the specification)

Signed-off-by: t.feng <fengtao40@huawei.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

grub-core/fs/bfs.c

@@ -416,6 +416,8 @@ read_bfs_file (grub_disk_t disk,
 	len -= read_size;
 	buf = (char *) buf + read_size;
       }
+    grub_free (l1_entries);
+    grub_free (l2_entries);
     return GRUB_ERR_NONE;
   }
 }