Per direction from the slurm team, change the envar we look at to get our allocation

This commit was SVN r21915.

orte/mca/ras/slurm/ras_slurm_module.c

@@ -86,19 +86,13 @@ static int orte_ras_slurm_allocate(opal_list_t *nodes)
     }
     regexp = strdup(slurm_node_str);
     
-    tasks_per_node = getenv("SLURM_JOB_CPUS_PER_NODE");
-    if (NULL == tasks_per_node) {
-        /* didn't find SLURM 1.2 or above envar - look for prior
-         * version
-         */
     tasks_per_node = getenv("SLURM_TASKS_PER_NODE");
     if (NULL == tasks_per_node) {
         /* couldn't find any version - abort */
         orte_show_help("help-ras-slurm.txt", "slurm-env-var-not-found", 1,
-                           "SLURM_JOB_CPUS_PER NODE or SLURM_TASKS_PER_NODE");
+                       "SLURM_TASKS_PER_NODE");
         return ORTE_ERR_NOT_FOUND;
     }
-    }
     node_tasks = strdup(tasks_per_node);
 
     if(NULL == regexp || NULL == node_tasks) {