wifi: ipw2100: fix warnings about non-kernel-doc

Just remove the extra asterisk to make it not be
kernel-doc formatted.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220904212910.8169e8c9090c.I0357e80cc86be2d4ac6205d1f53568444dcf7c9b@changeid