drm/nouveau/gsp: fix mismatched alloc/free for kvmalloc()

Replace kfree() with kvfree() for memory allocated by kvmalloc().

Compile-tested only.

Cc: stable@vger.kernel.org
Fixes: 8a8b1ec ("drm/nouveau/gsp: split rpc handling out on its own")
Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
Reviewed-by: Timur Tabi <ttabi@nvidia.com>
Acked-by: Zhi Wang <zhiw@nvidia.com>
Link: https://lore.kernel.org/r/20250813125412.96178-1-rongqianfeng@vivo.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

Author: qianfengrong

drivers/gpu/drm/nouveau/nvkm/subdev/gsp/rm/r535/rpc.c

@@ -325,7 +325,7 @@ r535_gsp_msgq_recv(struct nvkm_gsp *gsp, u32 gsp_rpc_len, int *retries)
 
 		rpc = r535_gsp_msgq_peek(gsp, sizeof(*rpc), info.retries);
 		if (IS_ERR_OR_NULL(rpc)) {
-			kfree(buf);
+			kvfree(buf);
 			return rpc;
 		}
 
@@ -334,7 +334,7 @@ r535_gsp_msgq_recv(struct nvkm_gsp *gsp, u32 gsp_rpc_len, int *retries)
 
 		rpc = r535_gsp_msgq_recv_one_elem(gsp, &info);
 		if (IS_ERR_OR_NULL(rpc)) {
-			kfree(buf);
+			kvfree(buf);
 			return rpc;
 		}