msi: Don't fail if the directory already exists in MsiCreateAndVerifyInstallerDirectory.
[wine] / dlls / msvcr70 /
drwxr-xr-x   ..
-rw-r--r-- 104 Makefile.in
-rw-r--r-- 1150 msvcr70.c
-rw-r--r-- 41565 msvcr70.spec