[PATCH][next] drm/nouveau: fence: Avoid -Wflex-array-member-not-at-end warning

["Gustavo A. R. Silva" <gustavoars@kernel.org>]

-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/gpu/drm/nouveau/nouveau_fence.c:188:38: 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>
---
 drivers/gpu/drm/nouveau/nouveau_fence.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_fence.c b/drivers/gpu/drm/nouveau/nouveau_fence.c
index 7cc84472cece..7622587f149e 100644
--- a/drivers/gpu/drm/nouveau/nouveau_fence.c
+++ b/drivers/gpu/drm/nouveau/nouveau_fence.c
@@ -184,10 +184,10 @@ nouveau_fence_context_new(struct nouveau_channel *chan, struct nouveau_fence_cha
 	struct nouveau_cli *cli = chan->cli;
 	struct nouveau_drm *drm = cli->drm;
 	struct nouveau_fence_priv *priv = (void*)drm->fence;
-	struct {
-		struct nvif_event_v0 base;
-		struct nvif_chan_event_v0 host;
-	} args;
+	DEFINE_RAW_FLEX(struct nvif_event_v0, args, data,
+			sizeof(struct nvif_chan_event_v0));
+	struct nvif_chan_event_v0 *host =
+				(struct nvif_chan_event_v0 *)args->data;
 	int ret;
 
 	INIT_WORK(&fctx->uevent_work, nouveau_fence_uevent_work);
@@ -207,12 +207,12 @@ nouveau_fence_context_new(struct nouveau_channel *chan, struct nouveau_fence_cha
 	if (!priv->uevent)
 		return;
 
-	args.host.version = 0;
-	args.host.type = NVIF_CHAN_EVENT_V0_NON_STALL_INTR;
+	host->version = 0;
+	host->type = NVIF_CHAN_EVENT_V0_NON_STALL_INTR;
 
 	ret = nvif_event_ctor(&chan->user, "fenceNonStallIntr", (chan->runlist << 16) | chan->chid,
 			      nouveau_fence_wait_uevent_handler, false,
-			      &args.base, sizeof(args), &fctx->event);
+			      args, __struct_size(args), &fctx->event);
 
 	WARN_ON(ret);
 }
-- 
2.43.0