MDEV-24788: mariadbd --help Can't lock aria control file

... '/var/lib/mysql/aria_log_control' for exclusive use, error: 11

As such don't lock under aria_readonly (which is set by opt_help in the handler
initialization.

Fixes: 8eba777c

mysql-test/main/mysqld--help-aria.result

-[ERROR] mariadbd: Can't lock aria aria_log_control for exclusive use, error: #. Will retry for 0 seconds
-[ERROR] Plugin 'Aria' init function returned error.
-[ERROR] Plugin 'Aria' registration as a STORAGE ENGINE failed.
-[Warning] Could not open mysql.plugin table: "Unknown storage engine 'Aria'". Some options may be missing from the help text
 #
 # Check that we don't write any data to wrong or not existing datadir
 #

mysql-test/main/mysqld--help-aria.test

@@ -2,15 +2,10 @@
 # Check errors from mysqld--help when providing different datadir
 #
 
-# We can't run this test on windows as windows doesn't provide file locking
-# which the first exec requires.
-
---source include/not_windows.inc
-
 --let $args=--table-cache=5 --max-connections=10 --log-warnings=1 --silent-startup --lower-case-table-names=1 --help --verbose
 
 --exec $MYSQLD_CMD $args > $MYSQL_TMP_DIR/mysqld--help2.txt 2> $MYSQL_TMP_DIR/mysqld--help2.err
---replace_regex /mysqld/mariadbd/ /\d\d\d\d-\d*-\d* *\d*:\d*:\d* \d* // /control file '.*aria_log_control'/aria_log_control/ /error: \d+/error: #/
+--replace_regex /mysqld/mariadbd/ /\d\d\d\d-\d*-\d* *\d*:\d*:\d* \d* //
 --cat_file $MYSQL_TMP_DIR/mysqld--help2.err
 
 --echo #

storage/maria/ma_control_file.c

@@ -314,7 +314,7 @@ CONTROL_FILE_ERROR ma_control_file_open(my_bool create_if_missing,
       errmsg= "Can't create file";
       goto err;
     }
-    if (lock_control_file(name, wait_for_lock))
+    if (!aria_readonly && lock_control_file(name, wait_for_lock))
     {
       error= CONTROL_FILE_LOCKED;
       errmsg= lock_failed_errmsg;
@@ -332,7 +332,7 @@ CONTROL_FILE_ERROR ma_control_file_open(my_bool create_if_missing,
   }
 
   /* lock it before reading content */
-  if (lock_control_file(name, wait_for_lock))
+  if (!aria_readonly && lock_control_file(name, wait_for_lock))
   {
     error= CONTROL_FILE_LOCKED;
     errmsg= lock_failed_errmsg;