pml/yalla: add missing #include <alloca.h>

ompi/mca/pml/yalla/pml_yalla.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) Mellanox Technologies Ltd. 2001-2011.  ALL RIGHTS RESERVED.
+ * Copyright (C) 2001-2011 Mellanox Technologies Ltd. ALL RIGHTS RESERVED.
  * Copyright (c) 2015      Research Organization for Information Science
  *                         and Technology (RIST). All rights reserved.
  * $COPYRIGHT$
@@ -9,6 +9,10 @@
  * $HEADER$
  */
 
+#ifdef HAVE_ALLOCA_H
+#include <alloca.h>
+#endif
+
 #include "pml_yalla.h"
 #include "pml_yalla_request.h"