msi: Don't fail if the directory already exists in MsiCreateAndVerifyInstallerDirectory.
[wine] / dlls / dhcpcsvc /
drwxr-xr-x   ..
-rw-r--r-- 61 Makefile.in
-rw-r--r-- 1324 dhcpcsvc.c
-rw-r--r-- 1345 dhcpcsvc.spec