remove "unused variable" warnings

[SVN r11426]

test/boost_has_clock_gettime.ipp

@@ -17,6 +17,7 @@ void f()
     // this is never called, it just has to compile:
     timespec tp;
     int res = clock_gettime(CLOCK_REALTIME, &tp);
+    (void) &res;
 }
 
 int test()

test/boost_has_gettimeofday.ipp

@@ -17,6 +17,7 @@ void f()
     // this is never called, it just has to compile:
     timeval tp;
     int res = gettimeofday(&tp, 0);
+    (void) &res;
 }
 
 int test()

test/boost_has_nanosleep.ipp

@@ -15,9 +15,10 @@ namespace boost_has_nanosleep{
 void f()
 {
     // this is never called, it just has to compile:
-    timespec ts = {0};
+    timespec ts = {0, 0};
     timespec rm;
     int res = nanosleep(&ts, &rm);
+    (void) &res;
 }
 
 int test()

test/boost_has_sched_yield.ipp

@@ -16,6 +16,7 @@ void f()
 {
     // this is never called, it just has to compile:
     int res = sched_yield();
+    (void) &res;
 }
 
 int test()