bcachefs: Print message on btree node read retry success

Right now, we print an error message on btree node read error, and we
print that we're retrying, but we don't explicitly say if the retry
succeeded - this makes things a little clearer.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

fs/bcachefs/btree_io.c

@@ -1141,10 +1141,12 @@ static void btree_node_read_work(struct work_struct *work)
 	struct bch_io_failures failed = { .nr = 0 };
 	struct printbuf buf = PRINTBUF;
 	bool saw_error = false;
+	bool retry = false;
 	bool can_retry;
 
 	goto start;
 	while (1) {
+		retry = true;
 		bch_info(c, "retrying read");
 		ca = bch_dev_bkey_exists(c, rb->pick.ptr.dev);
 		rb->have_ioref		= bch2_dev_get_ioref(ca, READ);
@@ -1174,8 +1176,11 @@ static void btree_node_read_work(struct work_struct *work)
 				&failed, &rb->pick) > 0;
 
 		if (!bio->bi_status &&
-		    !bch2_btree_node_read_done(c, ca, b, can_retry))
+		    !bch2_btree_node_read_done(c, ca, b, can_retry)) {
+			if (retry)
+				bch_info(c, "retry success");
 			break;
+		}
 
 		saw_error = true;