mysql_fix_privilege_tables is not available (nor needed) in a Windows CMake

build, so do not require it to be present in mysql-test-run.pl.

mysql-test/mysql-test-run.pl

@@ -1088,7 +1088,8 @@ sub executable_setup () {
     $exe_mysqladmin=     mtr_exe_exists("$path_client_bindir/mysqladmin");
     $exe_mysql=          mtr_exe_exists("$path_client_bindir/mysql");
     $exe_mysql_fix_system_tables=
-      mtr_script_exists("$glob_basedir/scripts/mysql_fix_privilege_tables");
+      mtr_script_exists("$glob_basedir/scripts/mysql_fix_privilege_tables",
+                        "/usr/bin/false");
     $path_ndb_tools_dir= mtr_path_exists("$glob_basedir/storage/ndb/tools");
     $exe_ndb_mgm=        "$glob_basedir/storage/ndb/src/mgmclient/ndb_mgm";
   }
@@ -1104,7 +1105,8 @@ sub executable_setup () {
     $exe_mysql=          mtr_exe_exists("$path_client_bindir/mysql");
     $exe_mysql_fix_system_tables=
       mtr_script_exists("$path_client_bindir/mysql_fix_privilege_tables",
-			"$glob_basedir/scripts/mysql_fix_privilege_tables");
+			"$glob_basedir/scripts/mysql_fix_privilege_tables",
+                        "/usr/bin/false");
     $exe_my_print_defaults=
       mtr_exe_exists("$path_client_bindir/my_print_defaults");