repair unused returns in perfio and test-runner

src/test/perf/perf-io.cc

@@ -50,7 +50,7 @@ PerfFile (FILE *file, uint32_t n, const char *buffer, uint32_t size)
 {
   for (uint32_t i = 0; i < n; ++i)
     {
-      fwrite (buffer, 1, size, file);
+      size_t __attribute__ ((unused)) result = fwrite (buffer, 1, size, file);
     }
 }
 

utils/test-runner.cc

@@ -107,7 +107,7 @@ BaseDir (void)
   // depends on the leading '/'
   //
   char pathbuf[PATH_MAX];
-  getcwd (pathbuf, sizeof(pathbuf));
+  char * __attribute__ ((unused)) p = getcwd (pathbuf, sizeof(pathbuf));
 
   //
   // Walk up the directory tree looking for a directory that has files that