##### 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)
checked = []
        self.fixed_lines = []
        for line in self.file_lines:
            if not line.strip() or line.strip().startswith(("#", ";")) or "=" not in line:
                self.fixed_lines.append(line)
                continue
            tmpline = line.strip()
            k, v = tmpline.split('=', 1)
            k = k.strip()
            v = v.strip()
            if k not in checked:
                checked.append(k)
                if k == self.args['name']:
                    if self.args['state'] == "present":
                        new_line = "%s=%s\n" % (k, self.args['value'])
                        self.fixed_lines.append(new_line)
                else:
                    new_line = "%s=%s\n" % (k, v)
                    self.fixed_lines.append(new_line)
        if self.args['name'] not in checked and self.args['state'] == "present":
            new_line = "%s=%s\n" % (self.args['name'], self.args['value'])
            self.fixed_lines.append(new_line)
    
    def write_sysctl(self):