Removed flappy test (race condition in test) [#CLICKHOUSE-3267].

dbms/tests/queries/0_stateless/00289_buffer_test.reference

-20000 1 20000 200010000 20000
-20000 1 20000 200010000 20000

dbms/tests/queries/0_stateless/00289_buffer_test.sh

-#!/usr/bin/env bash
-
-clickhouse-client -n --query="
-    DROP TABLE IF EXISTS test.dst;
-    DROP TABLE IF EXISTS test.buffer;
-
-    CREATE TABLE test.dst (x UInt64, d Date DEFAULT today()) ENGINE = MergeTree(d, x, 8192);
-    CREATE TABLE test.buffer (x UInt64, d Date DEFAULT today()) ENGINE = Buffer(test, dst, 16, 1, 10, 100, 1000, 10000, 100000);
-    ";
-
-seq    1 1000 | sed -r -e 's/^(.+)$/INSERT INTO test.buffer (x) VALUES (\1);/' | clickhouse-client -n &
-seq 1001 2000 | sed -r -e 's/^(.+)$/INSERT INTO test.buffer (x) VALUES (\1);/' | clickhouse-client -n &
-seq 2001 3000 | sed -r -e 's/^(.+)$/INSERT INTO test.buffer (x) VALUES (\1);/' | clickhouse-client -n &
-seq 3001 4000 | sed -r -e 's/^(.+)$/INSERT INTO test.buffer (x) VALUES (\1);/' | clickhouse-client -n &
-seq 4001 5000 | sed -r -e 's/^(.+)$/INSERT INTO test.buffer (x) VALUES (\1);/' | clickhouse-client -n &
-seq 5001 6000 | sed -r -e 's/^(.+)$/INSERT INTO test.buffer (x) VALUES (\1);/' | clickhouse-client -n &
-seq 6001 7000 | sed -r -e 's/^(.+)$/INSERT INTO test.buffer (x) VALUES (\1);/' | clickhouse-client -n &
-seq 7001 8000 | sed -r -e 's/^(.+)$/INSERT INTO test.buffer (x) VALUES (\1);/' | clickhouse-client -n &
-seq 8001 9000 | sed -r -e 's/^(.+)$/INSERT INTO test.buffer (x) VALUES (\1);/' | clickhouse-client -n &
-seq 9001 10000 | sed -r -e 's/^(.+)$/INSERT INTO test.buffer (x) VALUES (\1);/' | clickhouse-client -n &
-seq 10001 11000 | sed -r -e 's/^(.+)$/INSERT INTO test.buffer (x) VALUES (\1);/' | clickhouse-client -n &
-seq 11001 12000 | sed -r -e 's/^(.+)$/INSERT INTO test.buffer (x) VALUES (\1);/' | clickhouse-client -n &
-seq 12001 13000 | sed -r -e 's/^(.+)$/INSERT INTO test.buffer (x) VALUES (\1);/' | clickhouse-client -n &
-seq 13001 14000 | sed -r -e 's/^(.+)$/INSERT INTO test.buffer (x) VALUES (\1);/' | clickhouse-client -n &
-seq 14001 15000 | sed -r -e 's/^(.+)$/INSERT INTO test.buffer (x) VALUES (\1);/' | clickhouse-client -n &
-seq 15001 16000 | sed -r -e 's/^(.+)$/INSERT INTO test.buffer (x) VALUES (\1);/' | clickhouse-client -n &
-seq 16001 17000 | sed -r -e 's/^(.+)$/INSERT INTO test.buffer (x) VALUES (\1);/' | clickhouse-client -n &
-seq 17001 18000 | sed -r -e 's/^(.+)$/INSERT INTO test.buffer (x) VALUES (\1);/' | clickhouse-client -n &
-seq 18001 19000 | sed -r -e 's/^(.+)$/INSERT INTO test.buffer (x) VALUES (\1);/' | clickhouse-client -n &
-seq 19001 20000 | sed -r -e 's/^(.+)$/INSERT INTO test.buffer (x) VALUES (\1);/' | clickhouse-client -n &
-
-wait
-
-# To avoid race conditions (see comments in StorageBuffer.cpp)
-function retry()
-{
-    RES=$(clickhouse-client --query="$1")
-    if [[ $RES != "20000    1    20000    200010000    20000" ]]; then
-        sleep 10;
-        RES=$(clickhouse-client --query="$1");
-    fi;
-
-    echo $RES;
-}
-
-retry "SELECT count(), min(x), max(x), sum(x), uniqExact(x) FROM test.buffer;";
-clickhouse-client --query="OPTIMIZE TABLE test.buffer;";
-retry "SELECT count(), min(x), max(x), sum(x), uniqExact(x) FROM test.dst;";
-
-clickhouse-client -n --query="
-    DROP TABLE test.dst;
-    DROP TABLE test.buffer;
-    ";