fix setting of PMIX_NODE_RANK in cray pmix comp.

Per discussions with pmix folks, it was determined that
the way the cray pmi pmix component was computing the
PMIX_NODE_RANK attribute for a process was incorrect.
This commit fixes the problem.

This commit was SVN r32810.

opal/mca/pmix/cray/pmix_cray.c

@@ -230,7 +230,7 @@ static int cray_init(void)
     for (i=0; i < pmix_nlranks; i++) {
         if (pmix_rank == pmix_lranks[i]) {
             pmix_lrank = i;
-            pmix_nrank = my_node;
+            pmix_nrank = i;
             break;
         }
     }