##### SUMMARY

```
master:/usr/local/lib/python2.7/site-packages/ansible/modules/system/sysctl.py", line 297, in reload_sysctl
UnboundLocalError: local variable 'err' referenced before assignment
```

- Bug exists in Ansible 2.7.11 and the latest git repo
- Related source file: https://github.com/ansible/ansible/blob/devel/lib/ansible/modules/system/sysctl.py#L278

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME

- sysctl

##### ANSIBLE VERSION
```paste below
$ ansible --version
ansible 2.7.11
  config file = /Users/zhb/projects/pro/ansible.cfg
  configured module search path = [u'/Users/zhb/.ansible/plugins/modules', u'/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/local/lib/python2.7/site-packages/ansible
  executable location = /usr/local/bin/ansible
  python version = 2.7.16 (default, May 24 2019, 09:49:36) [GCC 4.2.1 Compatible Apple LLVM 10.0.1 (clang-1001.0.46.4)]
```

##### OS / ENVIRONMENT

- Host OS: macOS 10.14.5
- Target OS: OpenBSD 6.5 (amd64)
lines = []
        if os.path.isfile(self.sysctl_file):
            try:
                with open(self.sysctl_file, "r") as read_file:
                    lines = read_file.readlines()
            except IOError as e:
                self.module.fail_json(msg="Failed to open %s: %s" % (to_native(self.sysctl_file), to_native(e)))
        for line in lines:
            line = line.strip()
            self.file_lines.append(line)
            
            if not line or line.startswith(("#", ";")) or "=" not in line:
                continue
            k, v = line.split('=', 1)
            k = k.strip()
            v = v.strip()
            self.file_values[k] = v.strip()
    
    def fix_lines(self):