monitoring_test.c: remove unused var

Silence compiler warning

test/monitoring/monitoring_test.c

@@ -3,6 +3,7 @@
  *                         of Tennessee Research Foundation.  All rights
  *                         reserved.
  * Copyright (c) 2013-2015 Inria.  All rights reserved.
+ * Copyright (c) 2015 Cisco Systems, Inc.  All rights reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -78,7 +79,7 @@ I	3	2	860 bytes	24 msgs sent
 static MPI_T_pvar_handle flush_handle;
 static const char flush_pvar_name[] = "pml_monitoring_flush";
 static const char flush_cvar_name[] = "pml_monitoring_enable";
-static int flush_pvar_idx, flush_cvar_idx;
+static int flush_pvar_idx;
 
 int main(int argc, char* argv[])
 {