radv: Fix event write cmdbuffer allocation when tracing.

The trace emit is another 7 words.

Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7091>
diff --git a/src/amd/vulkan/radv_cmd_buffer.c b/src/amd/vulkan/radv_cmd_buffer.c
index 5e3a9f7..72c2934 100644
--- a/src/amd/vulkan/radv_cmd_buffer.c
+++ b/src/amd/vulkan/radv_cmd_buffer.c
@@ -6310,7 +6310,7 @@
 
 	radv_cs_add_buffer(cmd_buffer->device->ws, cs, event->bo);
 
-	ASSERTED unsigned cdw_max = radeon_check_space(cmd_buffer->device->ws, cs, 21);
+	ASSERTED unsigned cdw_max = radeon_check_space(cmd_buffer->device->ws, cs, 28);
 
 	/* Flags that only require a top-of-pipe event. */
 	VkPipelineStageFlags top_of_pipe_flags =