Measure WaitLatch's timeout parameter in milliseconds, not microseconds.

The original definition had the problem that timeouts exceeding about 2100
seconds couldn't be specified on 32-bit machines.  Milliseconds seem like
sufficient resolution, and finer grain than that would be fantasy anyway
on many platforms.

Back-patch to 9.1 so that this aspect of the latch API won't change between
9.1 and later releases.

Peter Geoghegan

src/backend/replication/syncrep.c

@@ -251,7 +251,7 @@ SyncRepWaitForLSN(XLogRecPtr XactCommitLSN)
 		 * cancel/die signal or postmaster death regularly while waiting. Note
 		 * that timeout here does not necessarily release from loop.
 		 */
-		WaitLatch(&MyProc->waitLatch, 60000000L);
+		WaitLatch(&MyProc->waitLatch, 60000L);
 	}
 
 	/*

src/backend/replication/walsender.c

@@ -807,7 +807,7 @@ WalSndLoop(void)
 			/* Sleep */
 			WaitLatchOrSocket(&MyWalSnd->latch, MyProcPort->sock,
 							  true, pq_is_send_pending(),
-							  sleeptime * 1000L);
+							  sleeptime);
 
 			/* Check for replication timeout */
 			if (replication_timeout > 0 &&