msi: Don't fail if the directory already exists in MsiCreateAndVerifyInstallerDirectory.
[wine] / dlls / winsock.dll16 /
drwxr-xr-x   ..
-rw-r--r-- 154 Makefile.in
-rw-r--r-- 28883 socket.c
-rw-r--r-- 2769 winsock.dll16.spec
-rw-r--r-- 4463 winsock16.h