tools/widl/write_msft.c warnings

[Gerald Pfeifer]

The addition of tools/widl/write_msft.c added the following four warnings,
basically doubling the number of warnings we are getting with GCC 3.4.

write_msft.c:582: warning: `ctl2_alloc_importinfo' defined but not used
write_msft.c:620: warning: `ctl2_alloc_importfile' defined but not used
write_msft.c:918: warning: `ctl2_find_nth_reference' defined but not used
write_msft.c:1382: warning: `set_help_file_name' defined but not used

Would you mind looking into this?

Gerald