drm/amdgpu: fix another missing fence reference in the CS code

drm_sched_job_add_dependency() consumes the references of the gang
members. Only triggered by mesh shaders.
Signed-off-by: Christian König <christian.koenig@amd.com>
Fixes: 1728baa7 ("drm/amdgpu: use scheduler dependencies for CS")
Tested-by: Mike Lothian <mike@fireburn.co.uk>
Tested-by: Bert Karwatzki <spasswolf@web.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230105111703.52695-1-christian.koenig@amd.comReviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Luben Tuikov <luben.tuikov@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c

@@ -1254,10 +1254,13 @@ static int amdgpu_cs_submit(struct amdgpu_cs_parser *p,
 			continue;
 
 		fence = &p->jobs[i]->base.s_fence->scheduled;
+		dma_fence_get(fence);
 		r = drm_sched_job_add_dependency(&leader->base, fence);
-		if (r)
+		if (r) {
+			dma_fence_put(fence);
 			goto error_cleanup;
 		}
+	}
 
 	if (p->gang_size > 1) {
 		for (i = 0; i < p->gang_size; ++i)