Python lint: Use flake8 --extend-ignore instead of --ignore (#1498)

bazel/emscripten_toolchain/link_wrapper.py

@@ -24,7 +24,7 @@ import sys
 # Only argument should be @path/to/parameter/file
 assert sys.argv[1][0] == '@', sys.argv
 param_filename = sys.argv[1][1:]
-param_file_args = [l.strip() for l in open(param_filename, 'r').readlines()]
+param_file_args = [line.strip() for line in open(param_filename, 'r').readlines()]
 
 # Re-write response file if needed.
 if any(' ' in a for a in param_file_args):