peer: remove useless map call.

Signed-off-by: Fedor Indutny <fedor@indutny.com>

lib/bcoin/peer.js

@@ -365,9 +365,6 @@ Peer.prototype._handleInv = function handleInv(items) {
   // Always request advertised TXs
   var txs = items.filter(function(item) {
     return item.type === 'tx';
-  }).map(function(item) {
-    if (item.type === 'tx')
-      return item;
   });
 
   // Emit new blocks to schedule them between multiple peers