module: Remove unnecessary +1 from last_unloaded_module::name size

The variable last_unloaded_module::name tracks the name of the last
unloaded module. It is a string copy of module::name, which is
MODULE_NAME_LEN bytes in size and includes the NUL terminator. Therefore,
the size of last_unloaded_module::name can also be just MODULE_NAME_LEN,
without the need for an extra byte.

Fixes: e14af7ee ("debug: track and print last unloaded module in the oops trace")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Reviewed-by: Daniel Gomez <da.gomez@samsung.com>
Link: https://lore.kernel.org/r/20250630143535.267745-3-petr.pavlu@suse.com


Signed-off-by: Daniel Gomez <da.gomez@samsung.com>