MDEV-9970 - main.sp-threads fails sporadically

Added proper waiting for thread to enter required state. Also reduced amount of
information dumped from processlist.

mysql-test/r/sp-threads.result

@@ -32,12 +32,9 @@ update t1, t2 set val= 1 where id1=id2;
 call bug9486();
 lock tables t2 write;
 call bug9486();
-show processlist;
-Id	User	Host	db	Command	Time	State	Info	Progress
-#	root	localhost	test	Sleep	#		NULL	0.000
-#	root	localhost	test	Query	#	Waiting for table metadata lock	update t1, t2 set val= 1 where id1=id2	0.000
-#	root	localhost	test	Query	#	NULL	show processlist	0.000
-#	root	localhost	test	Sleep	#		NULL	0.000
+SELECT state,info FROM information_schema.processlist WHERE id=con1root_id;
+state	info
+Waiting for table metadata lock	update t1, t2 set val= 1 where id1=id2
 unlock tables;
 drop procedure bug9486;
 drop table t1, t2;

mysql-test/t/sp-threads.test

@@ -77,12 +77,15 @@ call bug9486();
 connection con2root;
 lock tables t2 write;
 connection con1root;
+let $con1root_id=`SELECT CONNECTION_ID()`;
 send call bug9486();
 connection con2root;
---sleep 2
 # There should be call statement in locked state.
---replace_column 1 # 3 localhost 6 #
-show processlist;
+let $wait_condition=SELECT COUNT(*)=1 FROM information_schema.processlist WHERE
+                    id=$con1root_id AND state='Waiting for table metadata lock';
+--source include/wait_condition.inc
+--replace_result $con1root_id con1root_id
+eval SELECT state,info FROM information_schema.processlist WHERE id=$con1root_id;
 unlock tables;
 connection con1root;
 reap;