staging: vt6655: Replace MACvSetCurrBCNLength with VNSvOutPortW

Replace macro MACvSetCurrBCNLength with VNSvOutPortW and as it
was the only user, it can now be removed.

Signed-off-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
Link: https://lore.kernel.org/r/8ff556c84b3a4a70e8151965bcf6357e1de61bd1.1653203927.git.philipp.g.hortmann@gmail.com


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