Small optimization.

This commit was SVN r10226.

ompi/datatype/dt_create_struct.c

@@ -29,7 +29,7 @@ int32_t ompi_ddt_create_struct( int count, const int* pBlockLength, const long*
     ompi_datatype_t *pdt, *lastType;
 
     if( 0 == count ) {
-        *newType = ompi_ddt_create( disp );
+        *newType = ompi_ddt_create( 0 );
         ompi_ddt_add( *newType, &ompi_mpi_datatype_null, 0, 0, 0);
         return OMPI_SUCCESS;
     }