test: sysfs: Fix cppcoreguidelines-special-member-functions

```
/home/andrew/src/openbmc/phosphor-led-sysfs/build/../test/sysfs.cpp:31:7: error: class 'FakeSysfsLed' defines a non-default destructor but does not define a copy constructor, a copy assignment operator, a move constructor or a move assignment operator [cppcoreguidelines-special-member-functions,-warnings-as-errors]
class FakeSysfsLed : public phosphor::led::SysfsLed
      ^
```

Change-Id: I180d0782fcb5c90a0e44f4023a3d146f1a408fb6
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
1 file changed