MDEV-262 : log_state occationally fails in buildbot.

The failures are  missing entries in the slow query log.  The reason for the failure  are sleep() calls  with short duration 10ms, which is less than the default system timer resolution for various WaitForXXXObject functions  (15.6 ms) and thus can't work reliably.
The fix is to make sleeps tiny bit longer (20ms from 10ms) in the test.

mysql-test/r/log_state.result

@@ -320,22 +320,22 @@ TRUNCATE TABLE mysql.slow_log;
 CREATE TABLE t1 (a INT);
 CREATE TABLE t2 (b INT, PRIMARY KEY (b));
 INSERT INTO t2 VALUES (3),(4);
-INSERT INTO t1 VALUES (1+sleep(.01)),(2);
-INSERT INTO t1 SELECT b+sleep(.01) from t2;
-UPDATE t1 SET a=a+sleep(.01) WHERE a>2;
-UPDATE t1 SET a=a+sleep(.01) ORDER BY a DESC;
-UPDATE t2 set b=b+sleep(.01) limit 1;
-UPDATE t1 SET a=a+sleep(.01) WHERE a in (SELECT b from t2);
-DELETE FROM t1 WHERE a=a+sleep(.01) ORDER BY a LIMIT 2;
+INSERT INTO t1 VALUES (1+sleep(.02)),(2);
+INSERT INTO t1 SELECT b+sleep(.02) from t2;
+UPDATE t1 SET a=a+sleep(.02) WHERE a>2;
+UPDATE t1 SET a=a+sleep(.02) ORDER BY a DESC;
+UPDATE t2 set b=b+sleep(.02) limit 1;
+UPDATE t1 SET a=a+sleep(.02) WHERE a in (SELECT b from t2);
+DELETE FROM t1 WHERE a=a+sleep(.02) ORDER BY a LIMIT 2;
 SELECT rows_examined,sql_text FROM mysql.slow_log;
 rows_examined	sql_text
-0	INSERT INTO t1 VALUES (1+sleep(.01)),(2)
-2	INSERT INTO t1 SELECT b+sleep(.01) from t2
-4	UPDATE t1 SET a=a+sleep(.01) WHERE a>2
-8	UPDATE t1 SET a=a+sleep(.01) ORDER BY a DESC
-2	UPDATE t2 set b=b+sleep(.01) limit 1
-4	UPDATE t1 SET a=a+sleep(.01) WHERE a in (SELECT b from t2)
-6	DELETE FROM t1 WHERE a=a+sleep(.01) ORDER BY a LIMIT 2
+0	INSERT INTO t1 VALUES (1+sleep(.02)),(2)
+2	INSERT INTO t1 SELECT b+sleep(.02) from t2
+4	UPDATE t1 SET a=a+sleep(.02) WHERE a>2
+8	UPDATE t1 SET a=a+sleep(.02) ORDER BY a DESC
+2	UPDATE t2 set b=b+sleep(.02) limit 1
+4	UPDATE t1 SET a=a+sleep(.02) WHERE a in (SELECT b from t2)
+6	DELETE FROM t1 WHERE a=a+sleep(.02) ORDER BY a LIMIT 2
 DROP TABLE t1,t2;
 TRUNCATE TABLE mysql.slow_log;
 # end of bug#49756

mysql-test/t/log_state.test

@@ -381,13 +381,13 @@ CREATE TABLE t2 (b INT, PRIMARY KEY (b));
 INSERT INTO t2 VALUES (3),(4);
 
 connect (con2,localhost,root,,);
-INSERT INTO t1 VALUES (1+sleep(.01)),(2);
-INSERT INTO t1 SELECT b+sleep(.01) from t2;
-UPDATE t1 SET a=a+sleep(.01) WHERE a>2;
-UPDATE t1 SET a=a+sleep(.01) ORDER BY a DESC;
-UPDATE t2 set b=b+sleep(.01) limit 1;
-UPDATE t1 SET a=a+sleep(.01) WHERE a in (SELECT b from t2);
-DELETE FROM t1 WHERE a=a+sleep(.01) ORDER BY a LIMIT 2;
+INSERT INTO t1 VALUES (1+sleep(.02)),(2);
+INSERT INTO t1 SELECT b+sleep(.02) from t2;
+UPDATE t1 SET a=a+sleep(.02) WHERE a>2;
+UPDATE t1 SET a=a+sleep(.02) ORDER BY a DESC;
+UPDATE t2 set b=b+sleep(.02) limit 1;
+UPDATE t1 SET a=a+sleep(.02) WHERE a in (SELECT b from t2);
+DELETE FROM t1 WHERE a=a+sleep(.02) ORDER BY a LIMIT 2;
 
 SELECT rows_examined,sql_text FROM mysql.slow_log;
 disconnect con2;