wil6210: wmi: Remove useless code

Fix the following whitescan warning:

An unsigned value can never be less than 0.

Reported-by: Abaci Robot <[e-mail]>
Signed-off-by: Jiapeng Chong <[e-mail]>
Signed-off-by: Kalle Valo <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/net/wireless/ath/wil6210/wmi.c

···
 	u8 cid = basic->cid;
 	struct wil_sta_info *sta;
 
-	if (cid < 0 || cid >= wil->max_assoc_sta) {
+	if (cid >= wil->max_assoc_sta) {
 		wil_err(wil, "invalid cid %d\n", cid);
 		return;
 	}