ot::Cli::Utils::LinkModeToString() method
Converts a given MLE Link Mode to flag string. The characters 'r', 'd', and 'n' are respectively used for `mRxOnWhenIdle`, `mDeviceType` and `mNetworkData` flags. If all flags are `false`, then "-" is returned.
Arguments
aLinkMode
The MLE Link Mode to convert.
aStringBuffer
A reference to an string array to place the string.
Return value
A pointer @p aStringBuffer which contains the converted string.