odls/alps: check if PMI gni rdma creds already set

Need to check if the alps odls component has already
read the rdma creds from alps.  Its okay to ask apshepherd
multiple times for rdma creds, but opal_setenv gets
a bit picky about this.  Rather than check for the OPAL_EXISTS
return value from opal_setenv, for now just check with
a static variable whether or not orte_odls_alps_get_rdma_creds
has already been successfully called before.

Would be nice to have an opal_getenv function for checking
if an env. variable had already been set by opal_putenv.

orte/mca/odls/alps/odls_alps_utils.c

@@ -53,6 +53,17 @@ int orte_odls_alps_get_rdma_creds(void)
     alpsAppGni_t *rdmacred_buf;
     char *ptr;
     char env_buffer[1024];
+    static int already_got_creds = 0;
+
+    /*
+     * If we already put the GNI RDMA credentials into orte_launch_environ,
+     * no need to do anything.
+     * TODO: kind of ugly, need to implement an opal_getenv
+     */
+
+    if (1 == already_got_creds) {
+        return ORTE_SUCCESS;
+    }
 
     /*
      * get the Cray HSN RDMA credentials here and stuff them in to the
@@ -234,6 +245,7 @@ int orte_odls_alps_get_rdma_creds(void)
     } 
 
    fn_exit:
+    if (ORTE_SUCCESS == ret) already_got_creds = 1;
     return ret;
 }