power: supply: cros_charge-control: Avoid -Wflex-array-member-not-at-end warning

-Wflex-array-member-not-at-end was introduced in GCC-14, and we are
getting ready to enable it, globally.

Replace an on-stack definition of a flexible structure with a call
to utility function cros_ec_cmd().

So, with these changes, fix the following warning:

drivers/power/supply/cros_charge-control.c:57:40: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]

Signed-off-by: Gustavo A. R. Silva <[e-mail]>
Acked-by: Thomas Weißschuh <[e-mail]>
Link: https://lore.kernel.org/r/aBEwnKtUOTYzS7C3@kspp
Signed-off-by: Sebastian Reichel <[e-mail]>

drivers/power/supply/cros_charge-control.c

···
 static int cros_chctl_send_charge_control_cmd(struct cros_ec_device *cros_ec,
 					      u8 cmd_version, struct ec_params_charge_control *req)
 {
+	int ret;
 	static const u8 outsizes[] = {
 		[1] = offsetof(struct ec_params_charge_control, cmd),
 		[2] = sizeof(struct ec_params_charge_control),
 		[3] = sizeof(struct ec_params_charge_control),
 	};
 
-	struct {
-		struct cros_ec_command msg;
-		union {
-			struct ec_params_charge_control req;
-			struct ec_response_charge_control resp;
-		} __packed data;
-	} __packed buf = {
-		.msg = {
-			.command = EC_CMD_CHARGE_CONTROL,
-			.version = cmd_version,
-			.insize  = 0,
-			.outsize = outsizes[cmd_version],
-		},
-		.data.req = *req,
-	};
+	ret = cros_ec_cmd(cros_ec, cmd_version, EC_CMD_CHARGE_CONTROL, req,
+			  outsizes[cmd_version], NULL, 0);
 
-	return cros_ec_cmd_xfer_status(cros_ec, &buf.msg);
+	if (ret < 0)
+		return ret;
+
+	return 0;
 }
 
 static int cros_chctl_configure_ec(struct cros_chctl_priv *priv)