Fail BRIN control functions during recovery explicitly

They already fail anyway, but prior to this patch they raise an ugly
error message about a lock that cannot be acquired.  This just improves
the message.

Author: Masahiko Sawada
Reported-by: Masahiko Sawada
Discussion: https://postgr.es/m/CAD21AoBZau4g4_NUf3BKNd=CdYK+xaPdtJCzvOC1TxGdTiJx_Q@mail.gmail.com
Reviewed-by: Kuntal Ghosh, Alexander Korotkov, Simon Riggs, Michaël Paquier, Álvaro Herrera

src/backend/access/brin/brin.c

@@ -871,6 +871,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Relation	heapRel;
 	double		numSummarized = 0;
 
+	if (RecoveryInProgress())
+		ereport(ERROR,
+				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+				 errmsg("recovery is in progress"),
+				 errhint("BRIN control functions cannot be executed during recovery.")));
+
 	if (heapBlk64 > BRIN_ALL_BLOCKRANGES || heapBlk64 < 0)
 	{
 		char	   *blk = psprintf(INT64_FORMAT, heapBlk64);
@@ -942,6 +948,12 @@ brin_desummarize_range(PG_FUNCTION_ARGS)
 	Relation	indexRel;
 	bool		done;
 
+	if (RecoveryInProgress())
+		ereport(ERROR,
+				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+				 errmsg("recovery is in progress"),
+				 errhint("BRIN control functions cannot be executed during recovery.")));
+
 	if (heapBlk64 > MaxBlockNumber || heapBlk64 < 0)
 	{
 		char	   *blk = psprintf(INT64_FORMAT, heapBlk64);