Misc cleanup.
* kern/command.c (grub_register_command_prio): Use
grub_zalloc() instead of explicitly zeroing data.
* kern/list.c: Include `<grub/mm.h>'.
(grub_named_list_find): Replace `0' with `NULL'.
* normal/autofs.c (struct grub_fs_module_list): Remove ad-hoc type.
(fs_module_list): Change type to `grub_named_list_t'. Update all
users.
* normal/dyncmd.c (read_command_list): Add space between function
call and parenthesis.
* normal/handler.c (read_handler_list): Likewise.