staging: wfx: check the vif ID of the Tx confirmations

When the driver has sent a frame on a virtual interface (vif), it
expects to receive the confirmation on the same vif.

This patch add a check for that.

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200701150707.222985-3-Jerome.Pouiller@silabs.com


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