Can't detect useless noqa in some cases

[MightyCreak]

Hi!

Thanks for your flake8 extension, already saved me quite some time!

I've met an issue though: it fails to detect that the "# noqa: E501" is not necessary in some cases:

# OK, detects E501 is useless: line + comment <= 79
my_array1 = ['lonnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnng string'],  # noqa: E501

# Fails to detect E501 is useless: line + comment > 79
my_array2 = ['lonnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnng string'],  # noqa: E501
my_array2 = ['lonnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnng string'],  # noqa: E501

# Fails to detect E501 is useless: the closing square bracket
my_array3 = [
    ['lonnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnng string'],  # noqa: E501
]  # noqa: E501

My flake8 command-line:

flake8 test_file.py

[plinss]

I was unable to reproduce the first two listed issues (perhaps fixed by changes to pydocstyle's behavior wrt noqa comments).

The last should be fixed.