Catch the raised exception so we can report failure (#42177)

[AWS iam_policy] Avoid the _undefined name_ by catching the raised exception into the variable __e__ so it can be reported on the following line.

flake8 testing of https://github.com/ansible/ansible on Python 3.6.3

$ __flake8 . --count --select=E901,E999,F821,F822,F823 --show-source --statistics__
```
./lib/ansible/modules/cloud/amazon/iam_policy.py:305:16: F821 undefined name 'e'
            if e.errno == 2:
               ^
./lib/ansible/modules/cloud/misc/rhevm.py:594:24: F821 undefined name 'e'
            setMsg(str(e))
                       ^
./lib/ansible/modules/files/archive.py:391:92: F821 undefined name 'e'
                module.fail_json(dest=dest, msg='Error deleting some source files: ' + str(e), files=errors)
                                                                                           ^
3    F821 undefined name 'e'
3
```

0 files changed, 0 insertions, 0 deletions