Remove needless uses of wxString::c_str() in wxString::Format...

... and similar wx "variadics," which all treat wxString smartly enough that
you don't need this.

Don't need c_str either to convert wxString to const wxChar * because
wxString has a conversion operator that does the same.

src/blockfile/LegacyBlockFile.cpp

@@ -83,7 +83,7 @@ void ComputeLegacySummaryInfo(const wxFileName &fileName,
       // FIXME: TRAP_ERR no report to user of absent summary files.
       if (!summaryFile.IsOpened()) {
          wxLogWarning(wxT("Unable to access summary file %s; substituting silence for remainder of session"),
-            fullPath.c_str());
+            fullPath);
 
          read = info->frames64K * info->bytesPerFrame;
          memset(data.ptr(), 0, read);