StartupXLOG: Call CleanupAfterArchiveRecovery after XLogReportParameters.

StartupXLOG: Call CleanupAfterArchiveRecovery after XLogReportParameters.

This does a better job grouping related operations together, since
all of the WAL records that we need to write prior to allowing WAL
writes generally and written by a single uninterrupted stretch of code.

Since CleanupAfterArchiveRecovery() just (1) runs recovery_end_command,
(2) removes non-parent xlog files, and (3) archives any final partial
segment, this should be safe, because all of those things are pretty
much unrelated to the WAL record written by XLogReportParameters().

Amul Sul, per a suggestion from me

Discussion: http://postgr.es/m/CAAJ_b97fysj6sRSQEfOHj-y8Jfd5uPqOgO74qast89B4WfD+TA@mail.gmail.com