Ignore leaks in openmpi's comm_split

tools/valgrind/openmpi.suppr

@@ -228,3 +228,12 @@
    fun:ompi_datatype_set_args
    fun:PMPI_Type_vector
 }
+
+{
+   suppr29
+   Memcheck:Leak
+   match-leak-kinds: indirect
+   ...
+   fun:PMPI_Comm_split
+   fun:main
+}