[peerdist] Start block download timers from within opener methods

Move the responsibility for starting the block download timers from
peerblk_expired() to peerblk_raw_open() and peerblk_retrieval_open(),
in preparation for adding the ability to defer calls to
peerblk_raw_open() via a block download queue.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/net/peerblk.c

 	if ( inject_fault ( PEERBLK_ANNUL_RATE ) )
 		intf_restart ( &peerblk->raw, 0 );
 
+	/* Start download attempt timer */
+	peerblk->rc = -ETIMEDOUT;
+	start_timer_fixed ( &peerblk->timer, PEERBLK_RAW_OPEN_TIMEOUT );
+
 	return 0;
 }
 
 	if ( inject_fault ( PEERBLK_ANNUL_RATE ) )
 		intf_restart ( &peerblk->retrieval, 0 );
 
+	/* Start download attempt timer */
+	peerblk->rc = -ETIMEDOUT;
+	start_timer_fixed ( &peerblk->timer, PEERBLK_RETRIEVAL_OPEN_TIMEOUT );
+
  err_open:
 	uri_put ( uri );
  err_uri:
 			continue;
 		}
 
-		/* Start download attempt timer */
-		peerblk->rc = -ETIMEDOUT;
-		start_timer_fixed ( &peerblk->timer,
-				    PEERBLK_RETRIEVAL_OPEN_TIMEOUT );
+		/* Peer download started */
 		return;
 	}
 
 	if ( ( rc = peerblk_raw_open ( peerblk ) ) != 0 )
 		goto err;
 
-	/* Start download attempt timer */
-	peerblk->rc = -ETIMEDOUT;
-	start_timer_fixed ( &peerblk->timer, PEERBLK_RAW_OPEN_TIMEOUT );
 	return;
 
  err: