btl/ugni: remove erroneous unlock

The endpoint lock was being released twice in mca_btl_ugni_get_ep.

Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>

opal/mca/btl/ugni/btl_ugni_add_procs.c

@@ -244,7 +244,6 @@ struct mca_btl_base_endpoint_t *mca_btl_ugni_get_ep (struct mca_btl_base_module_
     do {
         rc = opal_hash_table_get_value_uint64 (&ugni_module->id_to_endpoint, proc_id, (void **) &ep);
         if (OPAL_SUCCESS == rc) {
-            OPAL_THREAD_UNLOCK(&ugni_module->endpoint_lock);
             break;
         }