sysfs: Fix performance-move-const-arg

```
/home/andrew/src/openbmc/phosphor-led-sysfs/build/../sysfs.cpp:44:53: error: std::move of the const variable 'path' has no effect; remove std::move() or make the variable non-const [performance-move-const-arg,-warnings-as-errors]
    std::string content = getSysfsAttr<std::string>(std::move(path));
                                                    ^~~~~~~~~~    ~
```

Change-Id: I1fd99b58adac8cebecda64166a6929ad6885c366
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
1 file changed