fix lint and division by zero

Change-Id: Ia79d879399ad7f2d098fd4a0af5c29a89565133e

Author: lhutton1

python/tvm/topi/arm_cpu/injective.py

@@ -16,7 +16,6 @@
 # under the License.
 # pylint: disable=invalid-name, unused-variable
 """Schedule for pooling operators"""
-import numpy as np
 import tvm
 from tvm import te
 from ..utils import is_empty_shape
@@ -69,7 +68,8 @@ def schedule_injective(outs):
     if list(s[x].op.axis):
         # do not vectorize for broadcast
         dtype = "uint16" if x.dtype == "bfloat16" else x.dtype
-        (io, ii) = s[x].split(list(s[x].op.axis)[-1], 16 // (tvm.DataType(dtype).bits // 8))
+        itemsize = max(1, tvm.DataType(dtype).bits // 8)
+        (io, ii) = s[x].split(list(s[x].op.axis)[-1], 16 // itemsize)
         s[x].vectorize(ii)
     tvm.te.schedule.AutoInlineInjective(s)