module: sysfs: Simplify section attribute allocation

The existing allocation logic manually stuffs two allocations into one.
This is hard to understand and of limited value, given that all the
section names are allocated on their own anyways.
Une one allocation per datastructure.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20241227-sysfs-const-bin_attr-module-v2-4-e267275f0f37@weissschuh.net


Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>