infosoft/tests: Constify a character string

[Marvin]

Hi,

While running your changed tests on Windows, I think I found new failures.
Being a bot and all I'm not very good at pattern recognition, so I might be
wrong, but could you please double-check?
Full results can be found at
https://newtestbot.winehq.org/JobDetails.pl?Key=3827

Your paranoid android.


=== wvista (32 bit infosoft) ===
infosoft.c:183: Test failed: failed
infosoft.c:197: Test failed: failed

=== w2008s64 (32 bit infosoft) ===
infosoft.c:183: Test failed: failed
infosoft.c:197: Test failed: failed

=== w7pro64 (32 bit infosoft) ===
infosoft.c:183: Test failed: failed
infosoft.c:197: Test failed: failed

=== w2008s64 (64 bit infosoft) ===
infosoft.c:183: Test failed: failed
infosoft.c:197: Test failed: failed

=== w7pro64 (64 bit infosoft) ===
infosoft.c:183: Test failed: failed
infosoft.c:197: Test failed: failed