controller: Fix readability-identifier-naming

```
/home/andrew/src/openbmc/phosphor-led-sysfs/build/../controller.cpp:85:27: error: invalid case style for variable 'BUSNAME' [readability-identifier-naming,-warnings-as-errors]
    static constexpr auto BUSNAME = "xyz.openbmc_project.LED.Controller";
                          ^~~~~~~
                          busname
/home/andrew/src/openbmc/phosphor-led-sysfs/build/../controller.cpp:86:27: error: invalid case style for variable 'OBJPATH' [readability-identifier-naming,-warnings-as-errors]
    static constexpr auto OBJPATH = "/xyz/openbmc_project/led/physical";
                          ^~~~~~~
                          objpath
/home/andrew/src/openbmc/phosphor-led-sysfs/build/../controller.cpp:87:27: error: invalid case style for variable 'DEVPATH' [readability-identifier-naming,-warnings-as-errors]
    static constexpr auto DEVPATH = "/sys/class/leds/";
                          ^~~~~~~
                          devpath
```

Change-Id: I0ea55045d60704ff5744481fdb907cdebda80368
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
1 file changed