HBASE-7551 nodeChildrenChange event may happen after the transition to RS_ZK_REGION_SPLITTING in SplitTransaction causing the SPLIT event to be missed in the master side. (Ram, Ted, and Lars H)

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1433696 13f79535-47bb-0310-9956-ffa450edef68