iio: proximity: cros_ec_mkbp_proximity: 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.

Use the `DEFINE_RAW_FLEX()` helper for an on-stack definition of
a flexible structure where the size of the flexible-array member
is known at compile-time, and refactor the rest of the code,
accordingly.

So, with these changes, fix the following warning:

drivers/iio/proximity/cros_ec_mkbp_proximity.c:63:40: 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 <gustavoars@kernel.org>
Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
Link: https://patch.msgid.link/Z9lEYdPPIyiRGm36@kspp
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/proximity/cros_ec_mkbp_proximity.c b/drivers/iio/proximity/cros_ec_mkbp_proximity.c
index 667369b..d2ddb7d 100644 (file)
--- a/drivers/iio/proximity/cros_ec_mkbp_proximity.c
+++ b/drivers/iio/proximity/cros_ec_mkbp_proximity.c
@@ -59,16 +59,11 @@ static int cros_ec_mkbp_proximity_parse_state(const void *data)
 static int cros_ec_mkbp_proximity_query(struct cros_ec_device *ec_dev,
                                        int *state)
 {
-       struct {
-               struct cros_ec_command msg;
-               union {
-                       struct ec_params_mkbp_info params;
-                       u32 switches;
-               };
-       } __packed buf = { };
-       struct ec_params_mkbp_info *params = &buf.params;
-       struct cros_ec_command *msg = &buf.msg;
-       u32 *switches = &buf.switches;
+       DEFINE_RAW_FLEX(struct cros_ec_command, buf, data,
+                       MAX(sizeof(u32), sizeof(struct ec_params_mkbp_info)));
+       struct ec_params_mkbp_info *params = (struct ec_params_mkbp_info *)buf->data;
+       struct cros_ec_command *msg = buf;
+       u32 *switches = (u32 *)buf->data;
        size_t insize = sizeof(*switches);
        int ret;