staging: r8188eu: convert switch to if statement in mgt_dispatcher()

The 'switch (GetFrameSubType(pframe))' in mgt_dispatcher() has only
one case that does something different than the default case. Convert
the switch to an if statement to improve readability.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20220108082736.16788-3-straube.linux@gmail.com


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