cleanup lbs (#4163)

test/test_const_folding.py

@@ -1,14 +1,13 @@
 import unittest, math
 from tinygrad import Tensor, Device, dtypes
 from tinygrad.engine.schedule import create_schedule
-from tinygrad.features.multi import MultiLazyBuffer
 from tinygrad.helpers import CI
 from tinygrad.ops import BufferOps
 import numpy as np
 
 def _check_ast_count(desired_count:int, t:Tensor):
   # NOTE: this has side effect because everything can be scheduled only once
-  schedule = create_schedule(t.lazydata.lbs if isinstance(t.lazydata, MultiLazyBuffer) else [t.lazydata])
+  schedule = create_schedule(t.lazydata.lbs)
   asts = [s for s in schedule if s.ast[0].op is BufferOps.STORE]
   assert len(asts) == desired_count