drm/nouveau: fix pin refcnt leak in failure path

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_bo.c

@@ -333,7 +333,9 @@ nouveau_bo_pin(struct nouveau_bo *nvbo, uint32_t memtype)
 	nouveau_bo_placement_set(nvbo, memtype, 0);
 
 	ret = nouveau_bo_validate(nvbo, false, false);
-	if (ret == 0) {
+	if (ret)
+		goto out;
+
 	switch (bo->mem.mem_type) {
 	case TTM_PL_VRAM:
 		drm->gem.vram_available -= bo->mem.size;
@@ -344,11 +346,9 @@ nouveau_bo_pin(struct nouveau_bo *nvbo, uint32_t memtype)
 	default:
 		break;
 	}
-	}
 
 ref_inc:
 	nvbo->pin_refcnt++;
-
 out:
 	ttm_bo_unreserve(bo);
 	return ret;