Code clean-up using black and flake8

 - No functional change

Signed-off-by: Tim Hall <tim.hall@arm.com>
Change-Id: I5ab1198b9d092cd041fa9b85b2dee9900d299bfc
diff --git a/ethosu/vela/numeric_util.py b/ethosu/vela/numeric_util.py
index 9adf5ec..70209fb 100644
--- a/ethosu/vela/numeric_util.py
+++ b/ethosu/vela/numeric_util.py
@@ -86,5 +86,6 @@
         y = 1 / (1 + math.exp(-x))
     return y
 
+
 def full_shape(dim, shape, fill):
-    return ([fill] * (dim - len(shape))) + shape
\ No newline at end of file
+    return ([fill] * (dim - len(shape))) + shape