staging: wfx: fix (future) TDLS support

The device does not expect that the AP to have a link-id. However, TDLS
peers should have a a link-id.

The driver does not yet declare itself as supporting TDLS.
Notwithstanding, fix the code in anticipation of the support of TDLS.

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200427134031.323403-2-Jerome.Pouiller@silabs.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>