Both opal_shmem_base_select() and
opal_shmem_base_best_runnable_component_name() and were calling
opal_shmem_base_runtime_query(), which would do component selection
(and closing of losing components) twice.
Put protection in opal_shmem_base_runtime_query() to return the cached
results the second time. Additionally, make
opal_shmem_base_runtime_query() "own" the cached results
(vs. opal_shmem_base_select).
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