remove old incorrect bugfix that moved reading of procs_priv table into a separate function.

FLUSH PRIVILEGES no longer returns an error, when it was successful.
LOCK_grant is no longed unlocked/relocked between tables_priv and procs_priv

mysql-test/r/grant.result

@@ -1682,7 +1682,6 @@ use test;
 FLUSH PRIVILEGES without procs_priv table.
 RENAME TABLE mysql.procs_priv TO mysql.procs_gone;
 FLUSH PRIVILEGES;
-ERROR 42S02: Table 'mysql.procs_priv' doesn't exist
 Assigning privileges without procs_priv table.
 CREATE DATABASE mysqltest1;
 CREATE PROCEDURE mysqltest1.test() SQL SECURITY DEFINER

mysql-test/t/grant.test

@@ -1661,7 +1661,6 @@ use test;
 #
 --echo FLUSH PRIVILEGES without procs_priv table.
 RENAME TABLE mysql.procs_priv TO mysql.procs_gone;
---error ER_NO_SUCH_TABLE
 FLUSH PRIVILEGES;
 --echo Assigning privileges without procs_priv table.
 CREATE DATABASE mysqltest1;