wilc1000: Fix copy-and-paste typo in wilc_set_mac_address

The messages appears to have been copied from wilc_get_mac_address and
says "get" when it should say "set".

Signed-off-by: David Mosberger-Tang <davidm@egauge.net>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20211206232709.3192856-2-davidm@egauge.net