staging: wfx: simplify wfx_set_mcast_filter()

HIF functions return only serious errors (OOM or device freeze). The
current handling of errors in wfx_set_mcast_filter() does not bring
anything. Finally it may disturb the developer more than it helps.

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200115135338.14374-38-Jerome.Pouiller@silabs.com


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