[HBASE-9930] Remove validateResult function which converts the SENTINEL_RESULT…
Summary: This diff removes the validateResult() function which converts the SENTINEL_RESULT back to null in the get call also. This is not supposed to be done because the SENTINEL_RESULT.isEmpty() is true which is in coherence with the semantics of get.

Test Plan: Run TestFromClientSide

Reviewers: fan, adela, gauravm, daviddeng

Reviewed By: gauravm

CC: hbase-eng@

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.89-fb@1576884 13f79535-47bb-0310-9956-ffa450edef68