Fix flake8

pystencils/kerncraft_coupling/generate_benchmark.py

@@ -8,7 +8,7 @@ from jinja2 import Environment, PackageLoader, StrictUndefined
 from pystencils.astnodes import PragmaBlock
 from pystencils.backends.cbackend import generate_c, get_headers
 from pystencils.cpu.cpujit import get_compiler_config, run_compile_step
-from pystencils.data_types import get_base_type, to_ctypes
+from pystencils.data_types import get_base_type
 from pystencils.include import get_pystencils_include_path
 from pystencils.integer_functions import modulo_ceil
 from pystencils.sympyextensions import prod