ath6kl: wmi: Replace one-element array with flexible-array member in struct wmi_disconnect_event

Replace one-element array with flexible-array member in struct
wmi_disconnect_event.

This issue was found with the help of Coccinelle and audited and fixed,
manually.

Link: https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays
Link: https://github.com/KSPP/linux/issues/79Reviewed-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/e9957dc53ae48c2f39ae57b0157a67d844b5bc20.1645736204.git.gustavoars@kernel.org

drivers/net/wireless/ath/ath6kl/wmi.h

@@ -1596,7 +1596,7 @@ struct wmi_disconnect_event {
 	u8 disconn_reason;
 
 	u8 assoc_resp_len;
-	u8 assoc_info[1];
+	u8 assoc_info[];
 } __packed;
 
 /*