wifi: atmel: fix repeated words in comments

Delete the redundant word 'long'.

Signed-off-by: Jilin Yuan <yuanjilin@cdjrlc.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220709132637.16717-1-yuanjilin@cdjrlc.com