staging: r8188eu: replace switch-case with if

OnAction_p2p has a switch-case statement where only a single case is
handled. Use if instead, this makes the code shorter and easier to read.

Tested-by: Philipp Hortmann <philipp.g.hortmann@gmail.com> # Edimax N150
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20221030173326.1588647-8-martin@kaiser.cx


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