Fix a few valgrind-reported memory leaks

This commit was SVN r24498.

orte/mca/ess/singleton/ess_singleton_module.c

@@ -369,6 +369,7 @@ static int fork_hnp(void)
         close(death_pipe[0]);
         close(death_pipe[1]);
         free(cmd);
+        opal_argv_free(argv);
         return ORTE_ERR_SYS_LIMITS_CHILDREN;
     }
     
@@ -412,6 +413,7 @@ static int fork_hnp(void)
          */
         close(p[1]);  /* parent closes the write - orted will write its contact info to it*/
         close(death_pipe[0]);  /* parent closes the death_pipe's read */
+        opal_argv_free(argv);
         
         /* setup the buffer to read the name + uri */
         buffer_length = ORTE_URI_MSG_LGTH;

orte/util/session_dir.c

@@ -441,11 +441,14 @@ int orte_session_dir(bool create,
     /* 
      * Update some of the global structures if they are empty
      */
-    if (NULL == orte_process_info.tmpdir_base)
+    if (NULL == orte_process_info.tmpdir_base) {
         orte_process_info.tmpdir_base = strdup(local_prefix);
+    }
     
-    if (NULL == orte_process_info.top_session_dir)
+    if (NULL == orte_process_info.top_session_dir &&
+        NULL != frontend) {
         orte_process_info.top_session_dir = strdup(frontend);
+    }
 
     /*
      * Set the process session directory
@@ -495,10 +498,15 @@ int orte_session_dir(bool create,
     }
     
 cleanup:
-    if(NULL != fulldirpath)
+    if (NULL != local_prefix) {
+        free(local_prefix);
+    }
+    if(NULL != fulldirpath) {
         free(fulldirpath);
-    if(NULL != frontend)
+    }
+    if(NULL != frontend) {
         free(frontend);
+    }
     
     return rc;
 }