Rename wait event WalrcvExit to WalReceiverExit.

Commit de829ddf added wait event WalrcvExit. But its name is not
consistent with other wait events like WalReceiverMain or
WalReceiverWaitStart, etc. So this commit renames WalrcvExit to
WalReceiverExit.

Author: Fujii Masao
Reviewed-by: Thomas Munro
Discussion: https://postgr.es/m/cced9995-8fa2-7b22-9d91-3f22a2b8c23c@oss.nttdata.com

doc/src/sgml/monitoring.sgml

@@ -1763,8 +1763,8 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
        replication.</entry>
      </row>
      <row>
-      <entry><literal>WalrcvExit</literal></entry>
-      <entry>Waiting for the walreceiver to exit.</entry>
+      <entry><literal>WalReceiverExit</literal></entry>
+      <entry>Waiting for the WAL receiver to exit.</entry>
      </row>
      <row>
       <entry><literal>WalReceiverWaitStart</literal></entry>

src/backend/postmaster/pgstat.c

@@ -4121,8 +4121,8 @@ pgstat_get_wait_ipc(WaitEventIPC w)
 		case WAIT_EVENT_SYNC_REP:
 			event_name = "SyncRep";
 			break;
-		case WAIT_EVENT_WALRCV_EXIT:
-			event_name = "WalrcvExit";
+		case WAIT_EVENT_WAL_RECEIVER_EXIT:
+			event_name = "WalReceiverExit";
 			break;
 		case WAIT_EVENT_WAL_RECEIVER_WAIT_START:
 			event_name = "WalReceiverWaitStart";

src/backend/replication/walreceiverfuncs.c

@@ -224,7 +224,7 @@ ShutdownWalRcv(void)
 	ConditionVariablePrepareToSleep(&walrcv->walRcvStoppedCV);
 	while (WalRcvRunning())
 		ConditionVariableSleep(&walrcv->walRcvStoppedCV,
-							   WAIT_EVENT_WALRCV_EXIT);
+							   WAIT_EVENT_WAL_RECEIVER_EXIT);
 	ConditionVariableCancelSleep();
 }
 

src/include/pgstat.h

@@ -1008,7 +1008,7 @@ typedef enum
 	WAIT_EVENT_REPLICATION_SLOT_DROP,
 	WAIT_EVENT_SAFE_SNAPSHOT,
 	WAIT_EVENT_SYNC_REP,
-	WAIT_EVENT_WALRCV_EXIT,
+	WAIT_EVENT_WAL_RECEIVER_EXIT,
 	WAIT_EVENT_WAL_RECEIVER_WAIT_START,
 	WAIT_EVENT_XACT_GROUP_UPDATE
 } WaitEventIPC;