Remove tabs after spaces in C comments

This was not changed in HEAD, but will be done later as part of a
pgindent run.  Future pgindent runs will also do this.

Report by Tom Lane

Backpatch through all supported branches, but not HEAD

src/include/replication/walprotocol.h

@@ -81,7 +81,7 @@ typedef struct
 } StandbyHSFeedbackMessage;
 
 /*
- * Maximum data payload in a WAL data message.	Must be >= XLOG_BLCKSZ.
+ * Maximum data payload in a WAL data message.  Must be >= XLOG_BLCKSZ.
  *
  * We don't have a good idea of what a good value would be; there's some
  * overhead per message in both walsender and walreceiver, but on the other

src/include/replication/walreceiver.h

@@ -69,7 +69,7 @@ typedef struct
 	/*
 	 * latestChunkStart is the starting byte position of the current "batch"
 	 * of received WAL.  It's actually the same as the previous value of
-	 * receivedUpto before the last flush to disk.	Startup process can use
+	 * receivedUpto before the last flush to disk.  Startup process can use
 	 * this to detect whether it's keeping up or not.
 	 */
 	XLogRecPtr	latestChunkStart;