the verification of recvcount==0 and rank = root was braking

inter-communicator scatter, since the root (root==MPI_ROOT) might very well
have recvcount=0. The same fix has been applied to gather.c just the other way
round. 
 
Fixes the bug reported on the mainling list by Martin Audet. If there is a
1.2.7 this fix might be worthwhile porting it over.

Please note, that while the test works now for basic and for inter, we get a
0byte malloc warning from the inter module, which we still have to fix in a
separate patch.

This commit was SVN r18122.

ompi/mca/coll/basic/coll_basic_allgather.c

@@ -9,6 +9,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
+ * Copyright (c) 2008      University of Houston. All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow