Remove an unnecessary "else" from the generated Thrift code.

Remove an unnecessary "else" from the generated Thrift code.

The "if" block here always results in a return (or an exception),
so there is no need for an "else".  We can just put the rest of the code
under the "if" block.  This actually makes a little more sense because
the "if" block here is an exceptional case.

Also deleted a stale comment.

Reviewed By: lhastings

Test Plan: diff'ed the old and new code.

git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@665580 13f79535-47bb-0310-9956-ffa450edef68