Fix /tab, space mix usage

Author: zhhsplendid

tools/check_file_diff_approvals.sh

@@ -33,8 +33,8 @@ API_FILES=("CMakeLists.txt"
            "paddle/fluid/framework/ir/node.h"
            "paddle/fluid/framework/ir/graph.h"
            "paddle/fluid/framework/framework.proto"
-	   "python/paddle/distributed/__init"
-	   "python/paddle/distributed/fleet/__init__.py"
+           "python/paddle/distributed/__init"
+           "python/paddle/distributed/fleet/__init__.py"
            "python/requirements.txt"
            "python/paddle/fluid/__init__.py"
            "python/paddle/fluid/compiler.py"