Vendorize recent fixes in dsync (#3365)

* Update 'i' only if lock grant read from buffered channel

vendor/github.com/minio/dsync/README.md

@@ -16,7 +16,7 @@ This package was developed for the distributed server version of [Minio Object S
 For [minio](https://minio.io/) the distributed version is started as follows (for a 6-server system):
 
 ```
-$ minio server server1/disk server2/disk server3/disk server4/disk server5/disk server6/disk 
+$ minio server server1:/disk server2:/disk server3:/disk server4:/disk server5:/disk server6:/disk 
 ```
  
 _(note that the same identical command should be run on servers `server1` through to `server6`)_

vendor/github.com/minio/dsync/drwmutex.go

@@ -154,7 +154,7 @@ func (dm *DRWMutex) lockBlocking(isReadLock bool) {
 //
 func lock(clnts []RPC, locks *[]string, lockName string, isReadLock bool) bool {
 
-	// Create buffered channel of quorum size
+	// Create buffered channel of size equal to total number of nodes.
 	ch := make(chan Granted, dnodeCount)
 
 	for index, c := range clnts {
@@ -216,6 +216,8 @@ func lock(clnts []RPC, locks *[]string, lockName string, isReadLock bool) bool {
 						// We know that we are not going to get the lock anymore, so exit out
 						// and release any locks that did get acquired
 						done = true
+						// Increment the number of grants received from the buffered channel.
+						i++
 						releaseAll(clnts, locks, lockName, isReadLock)
 					}
 				}

vendor/github.com/minio/dsync/dsync.go

@@ -34,6 +34,7 @@ var ownNode int
 
 // Simple majority based quorum, set to dNodeCount/2+1
 var dquorum int
+
 // Simple quorum for read operations, set to dNodeCount/2
 var dquorumReads int
 
@@ -59,7 +60,7 @@ func SetNodesWithClients(rpcClnts []RPC, rpcOwnNode int) (err error) {
 
 	dnodeCount = len(rpcClnts)
 	dquorum = dnodeCount/2 + 1
-	dquorumReads = dnodeCount/2
+	dquorumReads = dnodeCount / 2
 	// Initialize node name and rpc path for each RPCClient object.
 	clnts = make([]RPC, dnodeCount)
 	copy(clnts, rpcClnts)

vendor/vendor.json

@@ -111,10 +111,10 @@
 			"revisionTime": "2015-11-18T20:00:48-08:00"
 		},
 		{
-			"checksumSHA1": "UWpLeW+oLfe/MiphMckp1HqKrW0=",
+			"checksumSHA1": "ddMyebkzU3xB7K8dAhM1S+Mflmo=",
 			"path": "github.com/minio/dsync",
-			"revision": "fcea3bf5533c1b8a5af3cb377d30363782d2532d",
-			"revisionTime": "2016-10-15T15:40:54Z"
+			"revision": "dd0da3743e6668b03559c2905cc661bc0fceeae3",
+			"revisionTime": "2016-11-28T22:07:34Z"
 		},
 		{
 			"path": "github.com/minio/go-homedir",