MDEV-11718 Post-fix

A better way of finding mysqld

mysql-test/mysql-test-run.pl

@@ -6190,7 +6190,8 @@ sub valgrind_arguments {
     mtr_add_arg($args, "--num-callers=16");
     mtr_add_arg($args, "--suppressions=%s/valgrind.supp", $glob_mysql_test_dir)
       if -f "$glob_mysql_test_dir/valgrind.supp";
-    my $temp= `ldd $ENV{MTR_BINDIR}/sql/mysqld | grep 'libjemalloc'`;
+    my $exe_mysqld= find_mysqld($bindir) || "";
+    my $temp= `ldd $exe_mysqld | grep 'libjemalloc'`;
     if ($temp)
     {
       mtr_add_arg($args, "--soname-synonyms=somalloc=libjemalloc*");