Use DECLARE_FLEX_ARRAY() helper in drivers/soc/qcom/smd-rpm.c

[GustavoARSilva]

diff -u -p ./drivers/soc/qcom/smd-rpm.c /tmp/nothing/drivers/soc/qcom/smd-rpm.c
--- ./drivers/soc/qcom/smd-rpm.c
+++ /tmp/nothing/drivers/soc/qcom/smd-rpm.c
@@ -75,7 +75,6 @@ struct qcom_rpm_message {
        __le32 length;
        union {
                __le32 msg_id;
-               u8 message[0];
        };
 };