loader: os console in options menu should use first name from list
The current os_console setup in options menu is assuming single value set in console variable. Since all usable device names for kernel have 4 chars, we can only compare first 4 chars, and ignore the rest. This does also follow the kernel logic to use first name from console variable (in case the os_console is not set).
Note the console variable setter function does validate the console names, so we always do have correct name(s) in console variable.
Testing done: verify the correct os_console value is set in options menu and on boot. With console="ttya,text", we should have os_console set to ttya. Note, full fix is provided with 14585.