drm/nouveau/drm/ttm: Remove set but not used variable 'mem'

drivers/gpu/drm/nouveau/nouveau_ttm.c: In function nouveau_vram_manager_new:
drivers/gpu/drm/nouveau/nouveau_ttm.c:66:22: warning: variable mem set but not used [-Wunused-but-set-variable]
drivers/gpu/drm/nouveau/nouveau_ttm.c: In function nouveau_gart_manager_new:
drivers/gpu/drm/nouveau/nouveau_ttm.c:106:22: warning: variable mem set but not used [-Wunused-but-set-variable]

They are not used any more, so remove it.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_ttm.c

@@ -63,14 +63,12 @@ nouveau_vram_manager_new(struct ttm_mem_type_manager *man,
 {
 	struct nouveau_bo *nvbo = nouveau_bo(bo);
 	struct nouveau_drm *drm = nouveau_bdev(bo->bdev);
-	struct nouveau_mem *mem;
 	int ret;
 
 	if (drm->client.device.info.ram_size == 0)
 		return -ENOMEM;
 
 	ret = nouveau_mem_new(&drm->master, nvbo->kind, nvbo->comp, reg);
-	mem = nouveau_mem(reg);
 	if (ret)
 		return ret;
 
@@ -103,11 +101,9 @@ nouveau_gart_manager_new(struct ttm_mem_type_manager *man,
 {
 	struct nouveau_bo *nvbo = nouveau_bo(bo);
 	struct nouveau_drm *drm = nouveau_bdev(bo->bdev);
-	struct nouveau_mem *mem;
 	int ret;
 
 	ret = nouveau_mem_new(&drm->master, nvbo->kind, nvbo->comp, reg);
-	mem = nouveau_mem(reg);
 	if (ret)
 		return ret;