wifi: brcmfmac: fix repeated words in comments

Delete the redundant words 'this' and 'and'.

Signed-off-by: Jilin Yuan <yuanjilin@cdjrlc.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220709133618.25958-1-yuanjilin@cdjrlc.com