perf: Optimized volume handling duplicateUUID logic to avoid quitting when volume is actualy normal

Under normal circumstances, there will be no problems, but when the
master is debugged in the local environment, the volume client cannot
communicate with the master normally, so the sendHeartBeat logic is
restarted, and a new connection is created to report the heartbeat. If
the master has not cleared the uuid of the volume at this time, then The
master will respond to volume duplicateUUIDS, and the volume service
will exit, but in fact the uuid of the volume is not duplicated

weed/storage/volume.go

@@ -293,7 +293,6 @@ func (v *Volume) collectStatus() (maxFileKey types.NeedleId, datFileSize int64,
 	fileCount = uint64(v.nm.FileCount())
 	deletedCount = uint64(v.nm.DeletedCount())
 	deletedSize = v.nm.DeletedSize()
-	fileCount = uint64(v.nm.FileCount())
 
 	return
 }