wifi: ath6kl: minor fix for allocation size

Although the "param" pointer occupies more or equal space compared
to "*param", the allocation size should use the size of variable
itself.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: bdcd8170 ("Add ath6kl cleaned up driver")
Signed-off-by: Alexey V. Vissarionov <gremlin@altlinux.org>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230117110414.GC12547@altlinux.org

drivers/net/wireless/ath/ath6kl/bmi.c

@@ -246,7 +246,7 @@ int ath6kl_bmi_execute(struct ath6kl *ar, u32 addr, u32 *param)
 		return -EACCES;
 	}
 
-	size = sizeof(cid) + sizeof(addr) + sizeof(param);
+	size = sizeof(cid) + sizeof(addr) + sizeof(*param);
 	if (size > ar->bmi.max_cmd_size) {
 		WARN_ON(1);
 		return -EINVAL;