smss: can't replace explorer with explorer_new by MoveFileEx

The provided movefileex_test_program.exe is a test application that replaces explorer.exe
with explorer_new.exe in "C:\ReactOS". But it didn't work correctly on ReactOS.

(1) Execute movefileex_test_program.exe on ReactOS.
(2) Restart ReactOS.
(3) explorer.exe didn't change. explorer_new.exe still exists.
explorer_old.exe appears.

This is a bug of MoveFileEx.

I found this bug when I tried to replace explorer.exe with explorer_new.exe.