staging: wfx: avoid c99 comments

The wfx driver is a network driver. C99 comments are prohibited in this
part of the kernel.

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20210913130203.1903622-28-Jerome.Pouiller@silabs.com


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