Vendor update for dsync, fixing major go routine leak issue. (#3308)

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

@@ -230,6 +230,7 @@ func lock(clnts []RPC, locks *[]string, lockName string, isReadLock bool) bool {
 			}
 
 			if done {
+				i++
 				break
 			}
 		}

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

@@ -45,8 +45,8 @@ func SetNodesWithClients(rpcClnts []RPC, rpcOwnNode int) (err error) {
 	// Validate if number of nodes is within allowable range.
 	if dnodeCount != 0 {
 		return errors.New("Cannot reinitialize dsync package")
-	} else if len(rpcClnts) < 4 {
-		return errors.New("Dsync not designed for less than 4 nodes")
+	} else if len(rpcClnts) < 2 {
+		return errors.New("Dsync not designed for less than 2 nodes")
 	} else if len(rpcClnts) > 16 {
 		return errors.New("Dsync not designed for more than 16 nodes")
 	} else if len(rpcClnts)&1 == 1 {

vendor/vendor.json

@@ -111,10 +111,10 @@
 			"revisionTime": "2015-11-18T20:00:48-08:00"
 		},
 		{
-			"checksumSHA1": "UWpLeW+oLfe/MiphMckp1HqKrW0=",
+			"checksumSHA1": "CthggCrV9rr2WmWv8BaqYRVZ5g0=",
 			"path": "github.com/minio/dsync",
-			"revision": "fcea3bf5533c1b8a5af3cb377d30363782d2532d",
-			"revisionTime": "2016-10-15T15:40:54Z"
+			"revision": "1c7e0305144281870a538dc21659c29c14dbe244",
+			"revisionTime": "2016-11-21T16:22:08Z"
 		},
 		{
 			"path": "github.com/minio/go-homedir",