MDEV-16708: Fixed ths issue with handling of ERR packet received by mysqltest

on response to COM_STMT_EXECUTE

The test cases like the following one
  delimiter |;
  CREATE PROCEDURE SP001()
  BEGIN
    DECLARE C1 CURSOR FOR SELECT 1;

    OPEN C1;

    SELECT 1;
    CLOSE C1;
    CLOSE C1;
  END|
  delimiter ;|
  --error 1326
  call SP001();

are failed since processing of ERR packet was missed by mysqltest
in case it is run with --ps-protocol

Additionally, the test sp-error was changed to don't run multi-statements
since they are not supported by PS protocol

client/mysqltest.cc

@@ -8324,6 +8324,7 @@ void run_query_stmt(struct st_connection *cn, struct st_command *command,
     goto end;
   }
 
+  int err;
   do
   {
     /*
@@ -8357,8 +8358,6 @@ void run_query_stmt(struct st_connection *cn, struct st_command *command,
       goto end;
     }
 
-    /* If we got here the statement was both executed and read successfully */
-    handle_no_error(command);
     if (!disable_result_log)
     {
       /*
@@ -8436,8 +8435,14 @@ void run_query_stmt(struct st_connection *cn, struct st_command *command,
         }
       }
     }
-  } while ( !mysql_stmt_next_result(stmt));
+  } while ( !(err= mysql_stmt_next_result(stmt)));
 
+  if (err > 0)
+    /* We got an error from mysql_next_result, maybe expected */
+    handle_error(command, mysql_errno(mysql), mysql_error(mysql),
+                 mysql_sqlstate(mysql), ds);
+  else
+    handle_no_error(command);
 end:
   if (!disable_warnings)
   {

mysql-test/main/sp-error.result

@@ -2771,7 +2771,7 @@ DROP TABLE t2;
 
 DROP PROCEDURE IF EXISTS p1;
 DROP PROCEDURE IF EXISTS p2;
-SET sql_mode = '';
+SET sql_mode = ''|
 CREATE PROCEDURE p1()
 BEGIN
 DECLARE var1 INTEGER DEFAULT 'string';
@@ -2782,7 +2782,7 @@ CALL p1()|
 Warnings:
 Warning	1366	Incorrect integer value: 'string' for column ``.``.`var1` at row 1
 
-SET sql_mode = DEFAULT;
+SET sql_mode = DEFAULT|
 CREATE PROCEDURE p2()
 BEGIN
 DECLARE EXIT HANDLER FOR SQLWARNING SELECT 'H2';

mysql-test/main/sp-error.test

@@ -3711,7 +3711,7 @@ DROP PROCEDURE IF EXISTS p2;
 
 delimiter |;
 
-SET sql_mode = '';
+SET sql_mode = ''|
 CREATE PROCEDURE p1()
 BEGIN
   DECLARE var1 INTEGER DEFAULT 'string';
@@ -3721,7 +3721,7 @@ END|
 --echo
 CALL p1()|
 --echo
-SET sql_mode = DEFAULT;
+SET sql_mode = DEFAULT|
 
 CREATE PROCEDURE p2()
 BEGIN