Fix missing declaration

mpi/examples/matrix_decomposition/mpi_cholesky_kernels.c

@@ -1,6 +1,6 @@
 /* StarPU --- Runtime system for heterogeneous multicore architectures.
  *
- * Copyright (C) 2009, 2010, 2012  Université de Bordeaux 1
+ * Copyright (C) 2009, 2010, 2012-2013  Université de Bordeaux 1
  * Copyright (C) 2010, 2011, 2012, 2013  Centre National de la Recherche Scientifique
  *
  * StarPU is free software; you can redistribute it and/or modify
@@ -16,6 +16,7 @@
  */
 
 #include <starpu.h>
+#include <math.h>
 #include "mpi_decomposition_params.h"
 #include "common/blas.h"
 #ifdef STARPU_USE_CUDA