ostest/sighand_test: sem need to be destroyed

Signed-off-by: hujun5 <hujun5@xiaomi.com>
diff --git a/testing/ostest/sighand.c b/testing/ostest/sighand.c
index de29355..82093a1 100644
--- a/testing/ostest/sighand.c
+++ b/testing/ostest/sighand.c
@@ -328,4 +328,6 @@
 
   printf("sighand_test: done\n");
   FFLUSH();
+  sem_destroy(&sem2);
+  sem_destroy(&sem1);
 }