staging: r8188eu: replace custom hwaddr_aton_i() with mac_pton()

Replace custom hwaddr_aton_i() with mac_pton() in core/ioctl_linux.c
and remove the now unused functions hwaddr_aton_i() and hex2num_i().

Acked-by: Phillip Potter <phil@philpotter.co.uk>
Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20210812132057.22579-1-straube.linux@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>