Fix typos in comments.

src/backend/replication/basebackup.c

@@ -752,7 +752,7 @@ SendBackupHeader(List *tablespaces)
 
 /*
  * Send a single resultset containing just a single
- * XlogRecPtr record (in text format)
+ * XLogRecPtr record (in text format)
  */
 static void
 SendXlogRecPtrResult(XLogRecPtr ptr, TimeLineID tli)

src/bin/pg_basebackup/receivelog.c

@@ -718,7 +718,7 @@ ReadEndOfStreamingResult(PGresult *res, XLogRecPtr *startpos, uint32 *timeline)
 }
 
 /*
- * The main loop of ReceiveXLogStream. Handles the COPY stream after
+ * The main loop of ReceiveXlogStream. Handles the COPY stream after
  * initiating streaming with the START_STREAMING command.
  *
  * If the COPY ends (not necessarily successfully) due a message from the