wifi: rt2x00: fix remove callback type mismatch

The function is used as remove callback for a platform driver.
It was missed during the conversion from int to void

Fixes: 0edb555a ("platform: Make platform_driver::remove() return void")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://patch.msgid.link/20250706092053.97724-1-nbd@nbd.name


Signed-off-by: Johannes Berg <johannes.berg@intel.com>