libceph: fix msgr keepalive flag

There was some broken keepalive code using a dead variable. Shift to using
the proper bit flag.

Signed-off-by: Sage Weil <[e-mail]>

include/linux/ceph/messenger.h

···
 	struct list_head out_queue;
 	struct list_head out_sent;   /* sending or sent but unacked */
 	u64 out_seq;		     /* last message queued for send */
-	bool out_keepalive_pending;
 
 	u64 in_seq, in_seq_acked;  /* last message received, acked */
 

net/ceph/messenger.c

···
 		ceph_msg_put(con->out_msg);
 		con->out_msg = NULL;
 	}
-	con->out_keepalive_pending = false;
 	con->in_seq = 0;
 	con->in_seq_acked = 0;
 }
···
 	/* Requeue anything that hasn't been acked */
 	list_splice_init(&con->out_sent, &con->out_queue);
 
-	/* If there are no messages in the queue, place the connection
-	 * in a STANDBY state (i.e., don't try to reconnect just yet). */
-	if (list_empty(&con->out_queue) && !con->out_keepalive_pending) {
-		dout("fault setting STANDBY\n");
+	/* If there are no messages queued or keepalive pending, place
+	 * the connection in a STANDBY state */
+	if (list_empty(&con->out_queue) &&
+	    !test_bit(KEEPALIVE_PENDING, &con->state)) {
 		set_bit(STANDBY, &con->state);
 	} else {
 		/* retry after a delay. */