staging: r8723au: use kernel preferred style for commenting

Reworked comments per kernel coding style to improve readability.

Corrects checkpatch.pl:
WARNING: Block comments use * on subsequent lines
WARNING: line over 80 characters

Signed-off-by: Alison Schofield <amsfield22@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>