ole32: Fix invalid memory access in storage32

[Huw Davies]

Nathan Gallaher wrote:
> 
> In StorageImpl_construct():
> For pwcsName strings shorter than DIRENTRY_NAME_BUFFER_LEN-1, an invalid
> read would be noted by valgrind as the memcpy wanders off the end of the
> string.  Do the needful to calculate the required string length.

By the way, in storage32.h the filename member of struct StorageBaseImpl is declared as
WCHAR filename[DIRENTRY_NAME_BUFFER_LEN];
shouldn't it be
WCHAR filename[DIRENTRY_NAME_MAX_LEN];
?

Huw.