Update out-of-date comment in StartupXLOG.

Commit 4b0d28de should have updated
this comment, but did not.

Thomas Munro

Discussion: http://postgr.es/m/CAEepm=0iJ8aqQcF9ij2KerAkuHF3SwrVTzjMdm1H4w++nfBf9A@mail.gmail.com

src/backend/access/transam/xlog.c

@@ -6563,10 +6563,7 @@ StartupXLOG(void)
 				StandbyMode = true;
 		}
 
-		/*
-		 * Get the last valid checkpoint record.  If the latest one according
-		 * to pg_control is broken, try the next-to-last one.
-		 */
+		/* Get the last valid checkpoint record. */
 		checkPointLoc = ControlFile->checkPoint;
 		RedoStartLSN = ControlFile->checkPointCopy.redo;
 		record = ReadCheckpointRecord(xlogreader, checkPointLoc, 1, true);