OSHMEM: fixes problem with local heap2heap copy
    
check for possibility of heap2heap copy was incorrect
in case when shared heaps have different virtual
addresses on same host.

It seems that ibv_exp_reg_mr() on CIB cards may return
different VAs for heap on same node. On CX3 addresses are
the same.

reviewed by miked

cmr=v1.8.2:reviewer=ompi-rm1.8